Patent Publication Number: US-2016239171-A1

Title: Information display apparatus, distribution apparatus, information display method, and non-transitory computer readable storage medium

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2015-028098 filed in Japan on Feb. 16, 2015. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an information display apparatus, a distribution apparatus, an information display method, and a non-transitory computer readable storage medium. 
     2. Description of the Related Art 
     Conventionally, there is a known technology for displaying various kinds of information on arbitrary information display apparatuses including smart devices such as smartphones or tablet personal computers (PCs), desktop PCs, and the like. As an example of the technology, there is a known technology for attracting interest in a predetermined content by displaying the content on a screen and changing display modes of the content in accordance with an operation performed by a user. For example, there is a known technology for displaying a web page and a content related to advertisement on a screen, and expanding an area for displaying the content when a user performs a scroll operation on the web page.
     Patent Document 1: Japanese Laid-open Patent Publication No. 2014-049095.   

     However, in the conventional technology as described above, in some cases, an appeal effect of information related to the content is not always high. For example, in the conventional technology, because the area for displaying the content is increased when a scroll operation is performed on the web page, the impression that a user who pays close attention to the web page gets from the content may be negative. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to at least partially solve the problems in the conventional technology. 
     According to one aspect of an embodiment, an information display apparatus includes a display unit that displays a first content and a second content different from the first content. The information display apparatus includes a control unit that, when a moving operation is performed on the first content, reduces a display area of the second content in a direction in which the moving operation is performed, without moving the second content, to thereby expand an area in which the first content is displayed. 
     According to the other aspect of an embodiment, a distribution apparatus includes a distribution unit that distributes control information to a terminal device that displays a first content and a second content different from the first content. The control information causes the terminal device to display the first content and the second content. The control information causes the terminal device to reduce, when a moving operation is performed on the first content, a display area of the second content without moving the second content, to thereby expand an area in which the first content is displayed. 
     The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an example of a terminal device according to an embodiment; 
         FIG. 2  is a diagram illustrating a configuration example of a distribution system according to the embodiment; 
         FIG. 3  is a diagram illustrating a configuration example of an advertisement distribution server according to the embodiment; 
         FIG. 4  is a diagram illustrating an example of information stored in an advertisement database according to the embodiment; 
         FIG. 5  is a diagram illustrating a configuration example of a content distribution server according to the embodiment; 
         FIG. 6  is a diagram illustrating a configuration example of the terminal device according to the embodiment; 
         FIG. 7  is a diagram for explaining an example of setting of an arrangement area and a visible area; 
         FIG. 8  is a diagram illustrating a first variation of a display process performed by the terminal device according to the embodiment; 
         FIG. 9  is a diagram for explaining a variation of the setting of the arrangement area and the visible area; 
         FIG. 10  is a diagram illustrating a second variation of the display process performed by the terminal device according to the embodiment; 
         FIG. 11  is a flowchart illustrating an example of the flow of the display process performed by the terminal device according to the embodiment; and 
         FIG. 12  is a diagram illustrating an example of a hardware configuration of a computer that implements functions of the advertisement distribution server. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Modes (hereinafter, referred to as “embodiments”) for carrying out an information display apparatus, a distribution apparatus, an information display method, and a non-transitory computer readable storage medium according to the present invention will be described in detail below with reference to the drawings. The information display apparatus, the distribution apparatus, the information display method, and the non-transitory computer readable storage medium of the present invention are not limited by the embodiments. In each of the embodiments below, the same components will be denoted by the same reference numerals and symbols, and description thereof will be omitted. 
     1. Example of Terminal Device  100   
     First, an example of a process performed by a terminal device  100  as an example of an information display apparatus will be described with reference to  FIG. 1 . FIG.  1  is a diagram illustrating an example of the terminal device according to the embodiment.  FIG. 1  illustrates an example in which the terminal device  100  displays a web page C 10  and a content C 20 . 
     The terminal device  100  illustrated in  FIG. 1  is a smart device, such as a smartphone or a tablet, and is a mobile terminal device that can communicate with an arbitrary server device via a wireless communication network, such as third generation (3G) or a long term evolution (LTE). The terminal device  100  includes an output unit  130 , such as a liquid crystal display. It is assumed that a touch panel is used in the terminal device  100 . That is, a user of the terminal device  100  performs various operations by touching a display surface (hereinafter, may be described as a screen) of the output unit  130  with a finger or a stylus. 
     The web page C 10  is a web page in which, for example, news, a weather forecast, an index or a content of received mail, a photo viewer, and various other contents are arranged, and which is described in a hyper text markup language (HTML), an extensible markup language (XML), or the like. It is assumed that, at the top of the web page C 10 , a space C 11  with the same size as a display size of the content C 20  or an arbitrary content that need not be viewed by a user is inserted. 
     In the following description, it is assumed that the web page C 10  is a web page of a so-called portal site. It is also assumed that the web page C 10  is a web page which is optimized for smart devices and whose display size in the horizontal direction is the same as a display size of the screen of the terminal device  100  in the horizontal direction. It is also assumed that the web page C 10  is a web page whose display size in the vertical direction is longer than a display size of the output unit  130  of the terminal device  100  in the vertical direction and in which contents related to a plurality of news, such as “news  1 ” to “news  5 ”, are arranged. 
     The web page C 10  may be a content in which, for example, news, a weather forecast, an index or a content of received mail, a photo viewer, and various other contents are independently arranged in tile shapes and in which an operation, an update, or the like can be performed for each of the contents arranged in the tile shapes. In this case, the size or the arrangement position of each of the tiles arranged in the web page C 10  may be automatically changed for each tile or may be changed in accordance with an operation performed by a user. The web page C 10  may be a web page described in an HTML, an XML, or the like. The web page C 10  as described above includes an input field for inputting a search keyword, a link to a different web page, or the like. 
     The content C 20  is a content displayed together with the web page C 10 , and is, for example, a content related to advertisement (hereinafter, described as an advertisement content). For example, the content C 20  is a content configured with a plurality of contents C 21  to C 23 . 
     More specifically, the content C 21  is an image including an upper one-third of the range of an image displayed as the content C 20 . The content C 22  is an image including upper two-thirds of the range of the image displayed as the content C 20 . The content C 23  is an image including the entire range of the image displayed as the content C 20 . 
     The content C 20  may be configured with a plurality of contents each being independent of the others, or may be configured such that a plurality of contents each being independent of the others are combined so as to provide a single different content as a whole. Furthermore, the content C 20  may be configured with an arbitrary number of contents. 
     As will be described later, the content C 20  is a content whose arrangement position and display position are set by using cascading style sheets (CSS), HTML5, or other scripts that can describe dynamic contents, and therefore whose display mode is changed in accordance with an operation performed by a user. For example, the content C 20  is a content including an image, a character, a graphic, a symbol, a moving image, or the like subjected to control for display, deletion, expansion, reduction, movement, rotation, playback, pause, or the like in accordance with an operation performed by a user. The content C 20  may be a web page described in an HTML, an XML, or the like, similarly to the web page C 10 . 
     It is assumed that the content related to advertisement is not only commercial and non-commercial advertisements, but also recruitment of volunteers, public service advertisements, notifications to the public, a part of information related to the web page C 10 , or any other arbitrary content. That is, as the content C 20 , not only a content including so-called advertisement related information, but also an image, a moving image, a character, a graphic, a symbol, a hyper link, or any other arbitrary content may be used as long as the content attracts interest of a user and conveys information contained in the content C 20  or information contained in a content (for example, a landing page or the like) related to the content C 20 . 
     The terminal device  100 , upon receiving distribution of the web page C 10 , transmits a distribution request to an advertisement distribution server  20  that distributes a content related to advertisement. Then, upon receiving distribution of the content C 20  as the content related to advertisement from the advertisement distribution server  20 , the terminal device  100  displays the web page C 10  and the content C 20 . 
     2. Process Performed by the Terminal Device  100   
     In the conventional technology, an area for displaying a predetermined content is expanded when a scroll operation is performed on the web page C 10 . However, in the conventional technology, an area in which the web page C 10  is displayed (hereinafter, described as a display area of the web page C 10 ) is reduced with the expansion of the area of the content. Therefore, if a user pays close attention to the web page, the impression that the user gets from the content may be negative and an appeal effect of information related to the content may not properly be achieved. 
     Conventionally, a display process has been performed to improve the number of impressions of the content by arranging the content within a range in which an initial display of the web page C 10  is provided. However, if a user scrolls the web page C 10  before distribution of the content, the number of impressions is counted based on the assumption that the content is viewed, even though the user does not actually view the content. 
     Furthermore, if the content is continuously displayed when the web page C 10  is scrolled, the user may get a negative impression from the content. In contrast, fees for advertisement distribution are charged with respect to user&#39;s viewing, selection, or the like, and therefore, it is preferable to provide the content related to advertisement such that the content can easily attract attention of the user. 
     2-1. Display Process 
     In view of the above, the terminal device  100  performs a display process as described below. First, the terminal device  100  displays the web page C 10  and the content C 20 . Then, if a scroll operation is performed on the web page C 10 , the terminal device  100  does not move the content C 20  but reduces an area of the content C 20  being displayed (hereinafter, described as a display area of the content C 20  and the same applies to the following) in a direction in which the scroll operation is performed, to thereby expand the size of the area in which the web page C 10  is displayed. 
     More specifically, the terminal device  100  displays the web page C 10  at the upper end of the screen, and arranges and displays the content C 20  in front of the web page C 10 . At the top of the web page C 10 , the space C 11  with the same size as the display size of the content C 20  is inserted. Therefore, the terminal device  100  displays an initial screen arranged such that the upper end of the web page C 10  excluding the space C 11  comes in contact with the lower end of the content C 20 . 
     The upper end of the web page C 10  or the content C 20  is an end that serves as a reference position when the web page C 10  or the content C 20  is displayed on the screen and that is arranged on the upper most side on the screen when the web page C 10  or the content C 20  is displayed. Furthermore, the lower end of the web page C 10  or the content C 20  is an end that is arranged on the lowermost side on the screen among the ends that appear when the web page C 10  or the content C 20  is displayed on the screen. 
     If a scroll operation for moving the web page C 10  or the content C 20  in the screen upward direction (hereinafter, described as an upward scroll operation) is performed, the terminal device  100  scrolls the web page C 10  and gradually reduces the display area of the content C 20  from the screen downward direction to the upward direction. The screen upward direction is a direction in which the upper end of the web page C 10  or the content C 20  is displayed on the screen of the terminal device  100 , and the screen downward direction is a direction in which the lower end of the web page C 10  or the content C 20  is arranged on the screen. In other words, the terminal device  100  gradually moves the lower end of the content C 20  in the screen upward direction in accordance with the scroll operation without moving the upper end of the content C 20 , to thereby gradually reduce the width of the display area of the content C 20 . 
     If the content C 20  is configured with a plurality of the contents C 21  to C 23 , the terminal device  100  reduces the display area of each of the contents C 21  to C 23  at a different timing, for each of the contents C 21  to C 23 . For example, the terminal device  100  forms the content C 20  by arranging the content C 22  behind the content C 21  and arranging the content C 23  behind the content C 22  such that the positions of the respective upper ends of the contents C 21  to C 23  coincide with one another. 
     If an upward scroll operation is performed, the terminal device  100  gradually moves the lower end of the display area of the content C 23  in the screen upward direction without moving the content C 23 , to thereby gradually reduce the display area of the content C 23  in the screen upward direction. Furthermore, after the display area of the content C 23  is reduced such that the content C 23  is hidden behind the content C 22  and the display of the content C 23  disappears, if the upward scroll operation is further performed, the terminal device  100  gradually reduces the lower end of the display area of the content C 22  in the screen upward direction without moving the content C 22 , to thereby gradually reduce the display area of the content C 22  in the screen upward direction. 
     Moreover, after the display area of the content C 22  is reduced such that the content C 22  is hidden behind the content C 21  and the display of the content C 22  disappears, if the upward scroll operation is further performed, the terminal device  100  gradually reduces the display area of the content C 21  in the screen upward direction without moving the content C 21 . Consequently, the terminal device  100  gradually reduces the display area of the content C 20  in accordance with the scroll operation without moving the content C 20  and expands the display area of the web page C 10 . 
     The terminal device  100  may display the content C 20  by arranging, as the contents C 21  to C 23 , three equally-divided images of the content C 20  next to one another, and may simultaneously reducing the respective display areas of the contents C 21  to C 23  so as to gradually reduce the display area of the content C 20  in a slit shape. 
     Furthermore, the terminal device  100  sets a different timing to reduce the display area of each of the contents C 21  to C 23 . For example, the terminal device  100  displays the display area of the content C 22  without reducing the display area from when the display of the content C 23  disappears to when an amount of the upward scroll operation exceeds a predetermined threshold, and starts to reduce the display area of the content C 22  when the amount of the upward scroll operation exceeds the predetermined threshold. 
     Moreover, for example, the terminal device  100  may use different values as the amount of scroll to be performed from when the display of the entire content C 23  disappears to when the display area of the content C 22  starts to be reduced, and as the amount of scroll to be performed from when the display of the entire content C 22  disappears to when the display area of the content C 21  starts to be reduced. As described above, the terminal device  100  may reduce the size of the display area of the content C 20  in an arbitrary manner as long as the terminal device  100  can gradually reduce the size of the display area of the content C 20  without moving the content C 20  in accordance with a scroll operation performed on the web page C 10 . 
     Furthermore, the terminal device  100  may display a predetermined landing page when a user selects the content C 20 . The terminal device  100  may display a different landing page for each of the contents C 21  to C 23 , or may display a different landing page depending on the number of displayed contents among the contents C 21  to C 23 , a ratio of an area being displayed in the content C 20 , or the like. Moreover, when the contents C 21  to C 23  are not displayed, the terminal device  100  may perform a process such that the landing page is not displayed even when a user taps the positions at which the contents C 21  to C 23  have been arranged. 
     2-2. Method to Implement Display Process 
     The terminal device  100  can implement the above-described display process by an arbitrary method. For example, the terminal device  100  may monitor an amount of scroll, and if the monitored amount of scroll exceeds a predetermined threshold, the terminal device  100  may gradually reduce the display area of the content C 20  in accordance with the scroll operation. Furthermore, for example, the terminal device  100  determines whether a predetermined position of the web page C 10  is located in the screen upward direction relative to the lower end of the content C 20 . If the predetermined position of the web page C 10  is located in the screen upward direction relative to the lower end of the content C 20 , the terminal device  100  may move the lower end of the content C 20  to the predetermined position in the screen upward direction. 
     Moreover, the terminal device  100  may implement the above-described display process by using a script, such as CSS. For example, the terminal device  100  arranges the content C 20  in an arrangement area that is an area fixed at the upper end of the screen. Furthermore, the terminal device  100  sets, as a parent element of the content C 20 , a visible area that is an area in which the content C 20  is displayed in a visible state, from the upper end of the web page C 10  to a predetermined position. 
     If the arrangement area of the content C 20  is set, the terminal device  100  attempts to arrange and display the content C 20  on the arrangement area. However, if the visible area as the parent element is set, the terminal device  100  makes the content C 20  visible in only the visible area. Therefore, the terminal device  100  sets a visible state in only a range of the content C 20 , in which the content C 20  is arranged and the content C 20  is visible, that is, in which the arrangement area and the visible area overlap each other, and displays the range on the screen. 
     For example, in the initial screen, the entire arrangement area is included in the visible area of the content C 20 , that is, the arrangement area and the visible area coincide with each other. Therefore, the terminal device  100  displays the entire content C 20  in the initial screen. In contrast, if an upward scroll operation is performed, the visible area is moved in accordance with the scroll operation performed on the web page C 10 . Then, if the lower end of the content C 20  is moved in the screen upward direction relative to the lower end of the arrangement area, the arrangement area and the visible area do not coincide with each other, and only a range of the content C 20 , in which the arrangement area and the visible area overlap each other, is displayed. 
     Consequently, a range of the content C 20  from the lower end of the arrangement area to the lower end of the visible area is turned to an invisible state. Therefore, the terminal device  100  gradually reduces the display area of the content C 20  from the lower end of the display area without moving the content C 20 , and displays the web page C 10  arranged behind the content C 20 . That is, the invisible state described herein is not implemented by controlling the transparency or the like of the content C 20  by a program or a script, but is implemented by not displaying a range of the arrangement area that is not included in the visible area. 
     The terminal device  100  may separately set the visible area and the arrangement area for each of the contents C 21  to C 23 . For example, the terminal device  100  sets the arrangement areas of the contents C 21  to C 23  in sequence from the upper end of the screen, and sets the visible areas such that the lower ends are set at different positions. More specifically, the terminal device  100  sets the lower end of each of the visible areas such that gaps between the lower ends of the respective visible areas are greater than the width of the content C 21  in order of the content C 23 , the content C 22 , and the content C 21  from the upper end of the web page C 10 . Then, the terminal device  100  displays ranges of the contents C 21  to C 23  included in the visible areas. 
     If the above-described setting is performed, the terminal device  100  moves the lower end of the visible area of the content C 23  in the screen upward direction relative to the lower end of the arrangement area of the content C 23  through a scroll operation, to thereby gradually reduce the display area of the content C 23  from the lower end and make the content C 23  invisible. Furthermore, if the scroll operation is further performed, the terminal device  100  moves the lower end of the visible area of the content C 22  in the screen upward direction relative to the lower end of the arrangement area of the content C 22 , to thereby gradually reduce the display area of the content C 22  from the lower end and make the content C 22  invisible. Moreover, if the scroll operation is further performed, the terminal device  100  moves the lower end of the visible area of the content C 21  in the screen upward direction relative to the lower end of the arrangement area of the content C 21 , to thereby gradually reduce the display area of the content C 21  from the lower end and make the content C 21  invisible. 
     As described above, by setting the arrangement area of the content C 20  and the visible area as the parent element of the content C 20 , the terminal device  100  can gradually reduce the display area of the content C 20  without moving the content C 20  in accordance with a scroll operation performed on the web page C 10 . Therefore, the terminal device  100  can easily implement the above-described display process without performing a complicated process, such as a process of determining the amount of scroll or the position of the content C 10 . 
     2-3. Direction of Scroll Operation 
     If a scroll operation for moving the web page C 10  in the screen downward direction (hereinafter, described as a downward scroll operation) is performed, the terminal device  100  may gradually expand the display area of the content C 20 . For example, if the downward scroll operation is performed after the display area of the content C 20  is reduced, the terminal device  100  may expand the display area of the content C 20  by moving the lower end of the display area of the content C 20  in the screen downward direction without moving the content C 20 . 
     2-4. Example of Process Performed by the Terminal Device  100   
     An example of the display process performed by the terminal device  100  will be described below with reference to  FIG. 1 . In the following description, an example of a display process performed by the terminal device  100  to start to reduce the display area of each of the contents C 21  to C 23  at a different timing in order to gradually reduce the display area of the content C 20  including the contents C 21  to C 23  will be described in multiple parts, from a first state to a sixth state. Furthermore, in the following description, it is assumed that the lower end of the visible area of the content C 23  is arranged at the position of the upper end of the “news  1 ” contained in the web page C 10 , the lower end of the visible area of the content C 22  is arranged at the position of the upper end of the “news  2 ” contained in the web page C 10 , and the lower end of the visible area of the content C 21  is arranged at the position of the upper end of the “news  3 ” contained in the web page C 10 . 
     First, the terminal device  100  accepts distribution of the web page C 10  and the content C 20 . In this case, as illustrated in the first state, the terminal device  100  arranges the contents C 21  to C 23  next to one another from the upper end of the screen, and arranges and displays the web page C 10  from the upper end of the screen, to thereby display an initial screen in which the web page C 10  and the content C 20  are arranged next to each other. 
     If a user performs an upward scroll operation on the web page C 10  with a finger F 10 , the terminal device  100  scrolls the web page C 10  in the screen upward direction. If the upper end of the “news  1 ” contained in the web page C 10  is moved in the screen upward direction relative to the lower end of the content C 23 , that is, if the upper end of the visible area of the content C 23  is moved in the screen upward direction relative to the lower end of the arrangement area of the content C 23 , the terminal device  100  starts to reduce the display area of the content C 23  in accordance with the position of the upper end of the “news  1 ” as illustrated in the second state. 
     The terminal device  100  gradually reduces the display area of the content C 23  in accordance with the upward scroll operation and makes the content C 23  invisible as illustrated in the third state. In the example illustrated in the third state, the content C 23  is not entirely in the invisible state, but because a range in the visible state is arranged behind the content C 22 , the content C 23  is not displayed on the screen and is in the invisible state. 
     If the upward scroll operation is further performed, the terminal device  100  does not reduce the display area of the content C 22  but scrolls only the web page C 10 . Then, if the upper end of the “news  2 ” contained in the web page C 10  is moved in the screen upward direction relative to the lower end of the content C 22 , that is, if the upper end of the visible area of the content C 22  is moved in the screen upward direction relative to the lower end of the arrangement area of the content C 22  as a result of the upward scroll operation, the terminal device  100  starts to reduce the display area of the content C 22  in accordance with the position of the upper end of the “news  2 ” as illustrated in the fourth state. The terminal device  100  gradually reduces the display area of the content C 22  in accordance with the upward scroll operation, makes the content C 22  invisible similarly to the content C 23 , and displays only the content C 21  as illustrated in the fifth state. 
     Similarly, if the upward scroll operation is further performed, the terminal device  100  does not reduce the display area of the content C 21  but scrolls only the web page C 10 . If the upper end of the “news  3 ” contained in the web page C 10  is moved in the screen upward direction relative to the lower end of the content C 21 , that is, if the upper end of the visible area of the content C 21  is moved in the screen upward direction relative to the lower end of the arrangement area of the content C 21  as a result of the upward scroll operation, the terminal device  100  gradually reduces the display area of the content C 21  in accordance with the upward scroll operation. If the upper end of the “news  3 ” contained in the web page C 10  is moved to the upper end of the screen, the terminal device  100  makes the content C 21  invisible as illustrated in the sixth state. 
     If a downward scroll operation is performed, the terminal device  100  may display the content C 20  by gradually expanding the display area of each of the contents C 21  to C 23  in order from the contents C 21  to C 23  as illustrated in the sixth state to the first state. Furthermore, for example, the terminal device  100  may display a button or the like to hide the content C 20 , and may hide the entire content C 20  when the button is selected. Moreover, after hiding the entire content C 20 , the terminal device  100  may maintain the hidden state of the content C 20  even when a downward scroll operation or the like is performed. 
     As described above, if the user continuously performs the upward scroll operation, the terminal device  100  gradually makes the content C 20  invisible and expands the display area of the web page C 10 . More specifically, if a predetermined amount of a scroll operation is performed after the display area of the content C 23  is reduced and the content C 23  is made invisible in accordance with the scroll operation, the terminal device  100  starts a process for reducing the display area of the content C 22 . 
     Furthermore, if a predetermined amount of a scroll operation is performed after the content C 22  is made invisible, the terminal device  100  starts a process for reducing the display area of the content C 21 . By performing the above-described process, the terminal device  100  makes the contents C 21  to C 23  invisible in a complicated display mode such that the display areas of the contents C 21  to C 23  are gradually reduced at different timings, rather than simply reducing the display areas of the contents C 21  to C 23  in accordance with the scroll operation. 
     Therefore, the terminal device  100  can prevent a user from getting a negative impression of the content C 20  and can make the user aware of the content C 20 . Consequently, the terminal device  100  can cause the content C 20  to attract attention of a user who is interested in the content C 20 , and can improve an appeal of information related to the content C 20 . 
     Furthermore, even if a user immediately performs an upward scroll operation from the initial screen, the terminal device  100  does not immediately make the content C 20  invisible. Therefore, it is possible to ensure the first view of the content C 20  while preventing the user from getting a negative impression of the content C 20 . 
     Moreover, if an upward scroll operation is performed, the terminal device  100  hides the content C 20  in a complicated mode such that the terminal device  100  gradually moves the lower end of the content C 20  in the upward direction without moving the content C 20  in the upward direction. Therefore, the terminal device  100  can attract interest of the user in the content C 20 . 
     2-5. Execution Subject 
     The terminal device  100  can implement the above-described display process by using an arbitrary method, which has not been described above. For example, the terminal device  100  may implement the above-described process by downloading, in advance, an application that causes the terminal device  100  to execute the display process and by executing the application at an arbitrary timing. 
     Furthermore, at the same time of distribution of the web page C 10  and the content C 20 , the terminal device  100  accepts distribution of control information for executing the above-described display process. Then, the terminal device  100  performs the above-described display process in accordance with the control information. The terminal device  100  and the like that perform the display process illustrated in  FIG. 1  in accordance with the control information will be described below. 
     3. Configuration of Distribution System 
     The terminal device  100  and the like that implement the above-described display process will be described below. First, a configuration of a distribution system  1  according to the embodiment will be described with reference to  FIG. 2 .  FIG. 2  is a diagram illustrating a configuration example of the distribution system according to the embodiment. As illustrated in  FIG. 2 , the distribution system  1  includes the terminal device  100 , an advertiser terminal  10 , the advertisement distribution server  20 , and a content distribution server  30 . The terminal device  100 , the advertiser terminal  10 , the advertisement distribution server  20 , and the content distribution server  30  are communicably connected to one another by wire or wireless via a network N. The distribution system  1  illustrated in  FIG. 2  may include a plurality of the terminal devices  100 , a plurality of the advertiser terminals  10 , a plurality of the advertisement distribution servers  20 , and a plurality of the content distribution servers  30 . 
     The terminal device  100  is an information processing apparatus used by a user who views a web page. For example, the terminal device  100  is a mobile phone, such as a smartphone, a tablet terminal, a personal digital assistant (PDA), a desktop personal computer (PC), a notebook PC, or the like. The terminal device  100  acquires the web page C 10  from the content distribution server  30  in accordance with an operation performed by the user, and displays the acquired web page C 10 . If an acquisition command to be described later is included together with the web page C 10 , the terminal device  100  acquires the content C 20  from the advertisement distribution server  20 . Furthermore, upon accepting distribution of the control information for implementing the above-described display process from the advertisement distribution server  20 , the terminal device  100  operates in accordance with the control information and implements the display process. 
     The advertiser terminal  10  is an information processing apparatus used by an advertiser. For example, the advertiser terminal  10  is a desktop PC, a notebook PC, a tablet terminal, a mobile phone, a PDA, or the like. The advertiser terminal  10  submits an advertisement content, such as the content C 20 , to the advertisement distribution server  20  in accordance with an operation performed by the advertiser. For example, the advertiser terminal  10  submits, as the advertisement content, the content C 20  to the advertisement distribution server  20 . Furthermore, the advertiser terminal  10  submits, as the content C 20 , a uniform resource locator (URL) for acquiring a still image, a moving image, text data, a landing page, or the like to the advertisement distribution server  20 . 
     In some cases, the advertiser may request an agent to submit the advertisement content. In this case, the agent submits the advertisement content to the advertisement distribution server  20 . In the following, the “advertiser” is described as a concept including not only the advertiser but also the agent, and the “advertiser terminal” is described as a concept including not only the advertiser terminal  10  but also an agent terminal used by the agent. 
     The advertisement distribution server  20  is a server device that distributes the advertisement content submitted from the advertiser terminal  10 . For example, upon accepting a distribution request for an advertisement content from the terminal device  100 , the advertisement distribution server  20  performs matching between the user and an advertisement content based on a location of the terminal device  100 , an attribute of the user, or the like, and distributes the advertisement content determined as a distribution target as a result of the matching. Furthermore, the advertisement distribution server  20  distributes, to the terminal device  100 , the control information for implementing the above-described display process, together with the content C 20  as the advertisement content. The control information is described in a script language, such as JavaScript (registered trademark) or CSS. Meanwhile, the amount of offset of the display area may be distributed as the control information, or may be distributed as information separated from the control information. 
     The content distribution server  30  is a web server or the like that distributes the web page C 10  to the terminal device  100 . For example, the content distribution server  30  distributes, to the terminal device  100 , the web page C 10  in which various kinds of information related to a portal site, a news site, an auction site, a weather forecast site, a shopping site, a finance (stock price) site, a route search site, a map site, a travel site, a restaurant introduction site, a weblog, and the like are arranged in tile shapes. The content distribution server  30  may be a server that distributes a web page, such as a portal site, in which various kinds of information are arranged. 
     The web page C 10  distributed by the content distribution server  30  includes an acquisition command. For example, the URL or the like of the advertisement distribution server  20  is described, as the acquisition command, in an HTML file or the like that forms the web page C 10 . In this case, the terminal device  100  accesses the URL described in the HTML file or the like, and acquires the content C 20  as the advertisement content from the advertisement distribution server  20 . 
     Various kinds of data distributed from the content distribution server  30  to the terminal device  100  are, in practice, HTML files or images that form a web page, moving images displayed with the web page, or the like. 
     4. Configuration of Advertisement Distribution Server 
     A configuration of the advertisement distribution server  20  according to the embodiment will be described below with reference to  FIG. 3 .  FIG. 3  is a diagram illustrating a configuration example of the advertisement distribution server according to the embodiment. As illustrated in  FIG. 3 , the advertisement distribution server  20  includes a communication unit  21 , a storage unit  22 , and a control unit  23 . 
     The communication unit  21  is implemented by, for example, a network interface card (NIC) or the like. The communication unit  21  is connected to the network N by wire or wireless, and performs transmission and reception of information with the terminal device  100 , the advertiser terminal  10 , and the content distribution server  30 . 
     The storage unit  22  is implemented by, for example, a semiconductor memory device, such as a random access memory (RAM) or a flash memory, or a storage device, such as a hard disk or an optical disk. The storage unit  22  stores therein an advertisement database  24  as a database for storing various kinds of information related to an advertisement content submitted from the advertiser terminal  10 . 
       FIG. 4  is a diagram illustrating an example of information stored in the advertisement database according to the embodiment. In the example illustrated in  FIG. 4 , the advertisement database  24  contains items of an advertiser ID, an advertisement content, the number of impressions, the number of guaranteed impressions, and a consideration. The advertisement database  24  may further store therein information for performing matching between a content and a user, or information such as a click through rate (CTR). 
     The “advertiser ID” is identification information for identifying an advertiser or the advertiser terminal  10 . The “advertisement content” is a content submitted from the advertiser terminal  10 , that is, a content, such as the content C 20 , related to advertisement. In  FIG. 4 , an example is illustrated in which conceptual information, such as “C 20 ” to “C 60 ”, is stored in the “advertisement content”. However, in practice, a URL as a location of each of contents, such as an individual image, a moving image, audio and video, text data, game data, and an advertisement in a game format for conveying common information to a user, a file path name indicating a storage location of each of the contents, or the like is stored. 
     In the advertisement database  24 , a display instruction to instruct a change in the display mode of the content C 20  is registered as the advertisement content, in addition to the content C 20 . The display instruction includes setting values of the visible areas and the arrangement areas of the contents C 21  to C 23  included in the content C 20 . 
     For example, in the advertisement database  24 , the number of pixels, such as “0 to 1000 pixels” or “300 to 1000 pixels”, indicating a range of the visible area with reference to the upper end of the web page C 10  is registered for each of the contents C 21  to C 23 . Furthermore, in the advertisement database  24 , the number of pixels, such as “0 to 100 pixels” or “100 to 200 pixels”, indicating a range of the arrangement area with reference to the upper end of the screen is registered for each of the contents C 21  to C 23 . The terminal device  100  can change the display mode of the content C 20  in an arbitrary manner by a combination of the setting of the visible area and the setting of the arrangement area. 
     The display instruction includes information indicating an operation performed by a user, a status of the terminal device  100 , or the like to be a trigger for transition to a landing page of the content C 20 . For example, an advertiser performs arbitrary setting for the above-described display instruction when the advertiser registers an advertisement content. 
     The “number of impressions” indicates the number of times the advertisement content is displayed. The “number of guaranteed impressions” indicates the number of displays of an advertisement content guaranteed with respect to a consideration. The “consideration” indicates a compensation to be paid by the advertiser when the advertisement content is displayed by the “number of guaranteed impressions”. That is, the advertisement distribution server  20  is a server that distributes a content related to advertisement in an impression-guaranteed form. 
     Specifically,  FIG. 4  illustrates an example in which an advertiser identified by an advertiser ID “B 10 ” submits the content C 20  as the advertisement content. Furthermore,  FIG. 4  illustrates an example in which the number of impressions of the advertisement content “C 20 ” is “10000”, the number of guaranteed impressions is “20000”, and an amount of fees for displays of the content “C 20 ” by the number of guaranteed impressions is “aaa”. The advertisement distribution server  20  may count the number of impressions for each of the contents C 21  to C 23 . 
     When the content related to advertisement is distributed in a pay-per-click form in which a fee is charged every time the advertisement content is selected, the number of selections of the content, an amount of fees to be charged upon selection of the content, and the like are registered in the advertisement database  24 . Furthermore, when an advertisement content is selected in a bidding form and the selected advertisement content is distributed upon reception of a distribution request, a bid price as an advertisement fee that is set by the advertiser as a compensation per impression, a CTR, or the like is registered in the advertisement database  24 . 
     Referring back to  FIG. 3 , the description is continued. The control unit  23  is implemented by, for example, executing various programs stored in an internal storage device of the advertisement distribution server  20  by a central processing unit (CPU), a micro processing unit (MPU), or the like using a RAM as a work area. Furthermore, the control unit  23  is implemented by, for example, an integrated circuit, such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). 
     As illustrated in  FIG. 3 , the control unit  23  includes a submission accepting unit  25 , a request accepting unit  26 , an advertisement selecting unit  27 , and a distribution unit  28 , and implements or executes functions and operations of information processing as described below. The internal configuration of the control unit  23  is not limited to the configuration illustrated in  FIG. 3 , and any other configuration that performs the information processing as described below is applicable. Furthermore, a connection relation between processing units of the control unit  23  is not limited to the connection relation illustrated in  FIG. 3 , and any other connection relation is applicable. 
     The submission accepting unit  25  accepts submission of an advertisement content from the advertiser terminal  10 . Specifically, the submission accepting unit  25  accepts submission of an advertisement content together with designation of a consideration. Furthermore, the submission accepting unit  25  accepts the content C 20  and a display instruction. In this case, the submission accepting unit  25  registers the content C 20  and the display instruction in the advertisement database  24  together with the advertiser ID and a value of the accepted consideration. 
     The request accepting unit  26  accepts an acquisition request for an advertisement content from the terminal device  100 . For example, the request accepting unit  26  accepts an HTTP request as the acquisition request for the advertisement content. 
     When the request accepting unit  26  accepts the acquisition request for the advertisement content, the advertisement selecting unit  27  selects an advertisement content as a distribution candidate from the advertisement database  24 . For example, the advertisement selecting unit  27  performs matching of an advertisement content to be a distribution target among advertisement contents registered in the advertisement database  24 , on the basis of a location of the terminal device  100  or an attribute of the user. In the matching, the advertisement content is selected such that the number of impressions is greater than the number of guaranteed impressions. For example, the advertisement selecting unit  27  preferentially selects an advertisement content for which a difference between the number of guaranteed impressions and the number of impressions is the greatest. The advertisement selecting unit  27  may preferentially select an advertisement content with a high bid price or a high CTR, or an advertisement content with a high bid price and a high CTR. The advertisement selecting unit  27  outputs the advertisement content selected as the distribution target to the distribution unit  28 . 
     If a web page is a search page, the advertisement selecting unit  27  may use an advertisement distribution method called search advertising to extract an advertisement content that matches a search keyword specified in a search page. Furthermore, the advertisement selecting unit  27  may use an advertisement distribution method called targeted distribution to extract an advertisement content that matches attribute information (a psychographic attribute, a demographic attribute, or the like) of the user. 
     The distribution unit  28  distributes the control information to the terminal device  100  together with the advertisement content selected by the advertisement selecting unit  27 . Specifically, upon receiving the advertisement content selected by the advertisement selecting unit  27 , the distribution unit  28  extracts a display instruction contained in the received advertisement content. The distribution unit  28  generates control information for causing the terminal device  100  to perform a display process indicated by the extracted display instruction. The control information includes, for example, information indicating the positions of the visible area and the arrangement area of each of the contents C 21  to C 23 . Subsequently, the distribution unit  28  distributes the generated control information and the advertisement content to the terminal device  100 . 
     5. Configuration of Content Distribution Server 
     A configuration of the content distribution server  30  according to the embodiment will be described below with reference to  FIG. 5 .  FIG. 5  is a diagram illustrating a configuration example of the content distribution server according to the embodiment. As illustrated in  FIG. 5 , the content distribution server  30  includes a communication unit  31 , a content storage unit  32 , and a control unit  33 . 
     The communication unit  31  is implemented by, for example, a NIC or the like. The communication unit  31  is connected to the network N by wire or wireless, and performs transmission and reception of information with the terminal device  100  and the advertisement distribution server  20 . 
     The content storage unit  32  is implemented by, for example, a semiconductor memory device, such as a RAM or a flash memory, or a storage device, such as a hard disk or an optical disk. The content storage unit  32  stores therein a web page as an example of the content. For example, the content storage unit  32  stores therein an HTML file that forms a web page, or a still image or a moving image displayed on a web page. 
     The control unit  33  is implemented by, for example, executing various programs (corresponding to an example of a distribution program) stored in an internal storage device of the content distribution server  30  by a CPU, an MPU, or the like using a RAM as a work area. Furthermore, the control unit  33  is implemented by, for example, an integrated circuit, such as an ASIC or an FPGA. 
     As illustrated in  FIG. 5 , the control unit  33  includes an accepting unit  34  and a distribution unit  35 , and implements or executes functions and operations of information processing as described below. The internal configuration of the control unit  33  is not limited to the configuration illustrated in  FIG. 5 , and any other configuration that performs the information processing as described below is applicable. Furthermore, a connection relation between processing units of the control unit  33  is not limited to the connection relation illustrated in  FIG. 5 , and any other connection relation is applicable. 
     The accepting unit  34  accepts an acquisition request for a web page from the terminal device  100 . For example, the accepting unit  34  accepts an HTTP request as the acquisition request for a web page. 
     When the accepting unit  34  accepts the acquisition request for a web page, the distribution unit  35  distributes the web page to the terminal device  100 . Specifically, the distribution unit  35  acquires a web page as a target of the acquisition request from the content storage unit  32 , and distributes the acquired web page to the terminal device  100 . 
     Furthermore, the distribution unit  35  generates the web page C 10  and distributes the generated web page C 10  to the terminal device  100 . In this case, upon receiving the web page C 10 , the terminal device  100  transmits an advertisement distribution request to the advertisement distribution server  20  and displays an advertisement content received as a response. Then, the terminal device  100  performs a display process for changing the advertisement content in accordance with an operation performed by the user. 
     6. Configuration of Terminal Device 
     A configuration of the terminal device  100  according to the embodiment will be described below with reference to  FIG. 6 .  FIG. 6  is a diagram illustrating a configuration example of the terminal device according to the embodiment. As illustrated in  FIG. 6 , the terminal device  100  includes a communication unit  110 , an input unit  120 , the output unit  130 , a physical sensor  140 , and a control unit  150 . 
     The communication unit  110  is implemented by, for example, a NIC or the like. The communication unit  110  is connected to the network N by wire or wireless, and performs transmission and reception of information with the advertisement distribution server  20  and the content distribution server  30 . 
     The input unit  120  is an input device that accepts various operations from a user. For example, the input unit  120  is implemented by a keyboard, a mouse, an operation key, or the like. The output unit  130  is a display device that displays various kinds of information. For example, the output unit  130  is implemented by a liquid crystal display or the like. If a touch panel is used in the terminal device  100 , the input unit  120  and the output unit  130  are integrated with each other. In the following description, the output unit  130  may be described as a screen. 
     The physical sensor  140  is a sensor that detects a physical state of the terminal device  100 . For example, the physical sensor  140  is a gyro sensor that measures inclinations of the terminal device  100  in three axial directions. The physical sensor  140  is not limited to the gyro sensor, but an arbitrary sensor, such as an acceleration sensor, a temperature sensor, a volume sensor, or a brightness sensor, is applicable. 
     The control unit  150  is implemented by, for example, executing various programs (corresponding to an example of a display program) stored in an internal storage device of the terminal device  100  by a CPU, an MPU, or the like using a RAM as a work area. For example, the various programs correspond to an application program called a web browser. Furthermore, the control unit  150  is implemented by, for example, an integrated circuit, such as an ASIC or an FPGA. 
     As illustrated in  FIG. 6 , the control unit  150  includes a requesting unit  151 , an operation control unit  152 , and a display control unit  153 , and implements or executes functions and operations of information processing as described below. The internal configuration of the control unit  150  is not limited to the configuration illustrated in  FIG. 6 , and any other configuration that performs the information processing as described below is applicable. Furthermore, a connection relation between processing units of the control unit  150  is not limited to the connection relation illustrated in  FIG. 6 , and any other connection relation is applicable. 
     The requesting unit  151 , upon receiving the URL of the web page C 10  from the operation control unit  152 , transmits an acquisition request for the web page C 10  indicated by the received URL to the content distribution server  30 . Furthermore, if the web page C 10  received from the content distribution server  30  includes an acquisition command, the requesting unit  151  transmits an acquisition request for the advertisement content to the advertisement distribution server  20 . 
     The operation control unit  152  performs various kinds of control in accordance with a user&#39;s operation accepted via the input unit  120 . For example, if the user performs an operation of displaying the web page C 10  through the input unit  120 , the operation control unit  152  outputs the URL of the web page C 10  as a display target to the requesting unit  151 . Furthermore, the operation control unit  152  outputs the contents of the user&#39;s operation, such as a scroll operation or a tap operation, accepted through the input unit  120  to the display control unit  153 . 
     The display control unit  153  performs a process of displaying the received web page and the received advertisement content on the output unit  130 . For example, when the control unit  150  executes the control information distributed together with the advertisement content, the display control unit  153  operates as an arranging unit  154 , a display unit  155 , and an area control unit  156  as illustrated in  FIG. 6  and performs the display process. The arranging unit  154 , the display unit  155 , and the area control unit  156  are implemented by, for example, executing the control information by the CPU, the MPU, or the like using the RAM as a work area. 
     The arranging unit  154  arranges the contents C 21  to C 23  next to one another. For example, upon receiving a plurality of the contents C 21  to C 23  as the content C 20 , the arranging unit  154  arranges each of the contents C 21  to C 23  in the arrangement area of each of the contents C 21  to C 23  such that the contents C 21  to C 23  are displayed as the content C 20 . Furthermore, the arranging unit  154  arranges the web page C 10  behind each of the contents C 21  to C 23 . 
     The display unit  155  displays the web page C 10  and the content C 20 . Specifically, the display unit  155  displays the contents C 21  to C 23  and the web page C 10  arranged by the arranging unit  154 . Furthermore, the display unit  155  scrolls the web page C 10  in accordance with a scroll operation. Then, the display unit  155  displays only a range of each of the contents C 21  to C 23  included in the corresponding visible area. 
     The area control unit  156  moves the visible area of each of the contents C 21  to C 23  in accordance with the scroll operation performed on the web page C 10 , to thereby reduce the display area of each of the contents C 21  to C 23  in a direction in which the scroll operation is performed, without moving each of the contents C 21  to C 23 . Consequently, the area control unit  156  expands the size of the display area of the web page C 10 . 
     More specifically, the area control unit  156  moves the visible area set for each of the contents C 21  to C 23  in accordance with a scroll operation, similarly to the web page C 10 . Therefore, the area control unit  156  gradually and separately reduces the display area of each of the contents C 21  to C 23  from the screen downward direction to the upward direction in accordance with a scroll operation in the upward direction. 
     Incidentally, the respective lower ends of the visible areas C 21   b  to C 23   b  of the contents C 21  to C 23  are set at different positions. Therefore, by moving each of the visible areas, the area control unit  156  reduces the display area of each of the contents C 21  to C 23  at a different timing. Furthermore, the lower end of the visible area of each of the contents C 21  to C 23  are set in order of the content C 23 , the content C 22 , and the content C 21  with reference to the upper end of the web page C 10 . Therefore, the area control unit  156  starts to reduce the display area of each of the contents C 21  to C 23  in order of the content C 23 , the content C 22 , and the content C 21 . 
     Furthermore, if a space is provided between the lower end of the visible area C 23   b  and the lower end of the visible area C 22   b  and between the lower end of the visible area C 22   b  and the lower end of the visible area C 21   b , the terminal device  100  performs a display process as described below. Specifically, even if a scroll operation is performed after the content C 23  is made invisible, the terminal device  100  does not reduce the display area of the content C 22  for a while, and starts a process of reducing the display area of the content C 22  after a predetermined amount of the scroll operation is performed. Moreover, even if a scroll operation is performed after the content C 22  is made invisible, the terminal device  100  does not reduce the display area of the content C 21  for a while, and starts a process of reducing the display area of the content C 21  after a predetermined amount of the scroll operation is performed. 
     As described above, the terminal device  100  gradually reduces the display areas of the contents C 21  to C 23  at different timings. Therefore, for example, when displaying a content or the like whose display size in the vertical direction is long, the terminal device  100  displays the entire content and gradually reduces the display area in accordance with a scroll operation. Consequently, it is possible to prevent a user from getting a negative impression of the content and improve the appeal effect of the information related to the content. 
     7. Example of Setting of Arrangement Area and Visible Area 
       FIG. 7  is a diagram for explaining an example of setting of the arrangement area and the visible area. For example, in the example illustrated in (A) in  FIG. 7 , the arrangement area C 21   a  of the content C 21 , the arrangement area C 22   a  of the content C 22 , and the arrangement area C 23   a  of the content C 23  are set from the upper end of the web page C 10 . Furthermore, in the example illustrated in (A) in  FIG. 7 , the visible area C 23   b  of the content C 23  is set from the upper end of the web page, the visible area C 22   b  of the content C 22  is set such that a distance to the lower end is longer than that of the visible area C 23   b , and the visible area C 21   b  of the content C 21  is set such that a distance to the lower end is longer than that of the visible area C 22   b.    
     In this case, as illustrated in (B) in  FIG. 7 , the terminal device  100  arranges each of the contents C 21  to C 23  at the upper end of the screen of the output unit  130  and arranges the web page C 10  behind the contents C 21  to C 23 . In the example illustrated in (B) in  FIG. 7 , dotted lines schematically representing the visible areas C 21   b  to C 23   b  are arranged between the contents C 21  to C 23  and the web page C 10 . As indicated by (C) in  FIG. 7 , the terminal device  100  moves the web page C 10  and each of the visible areas C 21   b  to C 23  in accordance with a scroll operation. 
     The lower end of the visible area C 22   b  is set in the screen downward direction relative to the lower end of the visible area C 23   b , and the lower end of the visible area C 21   b  is set in the screen downward direction relative to the lower end of the visible area C 21   b . Therefore, the terminal device  100  moves the lower end of the visible area C 23   b  indicated by (D) in  FIG. 7  in the screen upward direction, to thereby make the content C 23  arranged in the arrangement area C 23   a  invisible from the lower end to the upper end. 
     Furthermore, after making the content C 23  invisible, the terminal device  100  moves the lower end of the visible area C 22   b  indicated by (E) in  FIG. 7  in the screen upward direction, to thereby gradually make the content C 22  arranged in the arrangement area C 22   a  invisible from the lower end to the upper end. Then, after making the content C 22  invisible, the terminal device  100  moves the lower end of the visible area C 21   b  indicated by (F) in  FIG. 7  in the screen upward direction, to thereby gradually make the content C 21  arranged in the arrangement area C 21   a  invisible from the upper end to the lower end. 
     If the content C 23  including the content C 22  as a part thereof is arranged behind the content C 22 , and the content C 23  is gradually made invisible from the lower end thereof in the screen upward direction, the terminal device  100  can display the content C 22  and the content C 23  such that the the contents C 22  and C 23  look seamless. However, the terminal device  100  may display different ranges of the content C 20  as the contents C 21  to C 23 . For example, if three contents equally divided from the upper end of the content C 20  are displayed as the contents C 21  to C 23 , the terminal device  100  may arrange the arrangement areas C 21   a  to C 23   a  next to one another from the upper end of the screen. Even when the above-described setting is performed, the terminal device  100  can implement the same display mode as the display mode obtained when the setting illustrated in  FIG. 7  is performed. 
     8. Variations of Display Process 
     An example of the display process performed by the terminal device  100  has been described above by using the display mode illustrated in  FIG. 1 . However, the embodiment is not limited to this example. Variations of the display process performed by the terminal device  100  will be described below. The display process described below is implemented by, for example, a process performed by the display unit  155  and the area control unit  156 . However, the embodiment is not limited to this example. 
     8-1. First Variation 
     The above-described terminal device  100  sets the visible areas that start from the upper end of the web page C 10 , and displays each of the contents C 21  to C 23  in the initial screen. Furthermore, the above-described terminal device  100  overlaps the respective visible areas of the contents C 21  to C 23 , sets the lower ends of the respective visible areas at different positions, and reduces the display areas at different timings. However, the embodiment is not limited to this example. 
     For example, a user may set the arrangement area of the content C 20  at the upper end of the screen and set the visible area in the middle of the web page C 10 . If the above-described setting is performed, the arrangement area and the visible area of the content C 20  do not overlap each other in the initial screen, so that the content C 20  is not displayed and only the web page C 10  is displayed. Then, the terminal device  100  displays the content C 20  such that when an upward scroll operation is performed, the terminal device  100  moves the lower end of the display area of the content C 20  in the screen upward direction without moving the content C 20  to thereby gradually expand the display area, and, when the upward scroll operation is further performed, the terminal device  100  gradually reduces the display area in the screen upward direction. 
     Therefore, the terminal device  100  displays only the web page C 10  without displaying the content C 20  in the initial screen, so that the user is not prevented from viewing the web page C 10 . Consequently, it is possible to prevent the user from getting a negative impression of the content C 20 . Furthermore, the terminal device  100  gradually displays the content C 20  from the lower end to the upper end when a scroll operation is performed, and thereafter gradually makes the content C 20  invisible from the lower end to the upper end. Therefore, the terminal device  100  can prevent the user from getting a negative impression of the content C 20  and improve the appeal of the information related to the content C 20 . 
     Moreover, for example, the user may set the arrangement areas of a plurality of the contents C 31  and C 32  of the same size at the same position, and may perform setting such that the lower end of the visible area of the content C 31  and the upper end of the visible area of the content C 32  come in contact with each other. If the above-described setting is performed, the terminal device  100  displays the content C 31  by gradually expanding the display area of the content C 31  from the screen downward direction to the screen upward direction in accordance with an upward scroll operation. 
     Furthermore, if the upward scroll operation is further performed, the terminal device  100  moves the lower end of the display area of the content C 31  in the screen upward direction, and simultaneously moves the upper end of the display area of the content C 32  in the screen upward direction within an area in which the content C 31  is displayed. Moreover, if the upward scroll operation is further performed, the terminal device  100  gradually reduces the display area of the content C 32 . By performing the above-described process, the terminal device  100  can switch from the content C 31  to the content C 32  in the same area on the screen in accordance with the scroll operation. 
     8-1-1. Setting of Visible Area and Arrangement Area 
     An example of variations of the display process will be described below with reference to  FIG. 8 .  FIG. 8  is a diagram illustrating a first variation of the display process performed by the terminal device according to the embodiment. In the following description, an example of the display process performed by the terminal device  100  to switch a content in the same area will be described in multiple parts, from a first state to a sixth state. 
     For example, as illustrated in  FIG. 8 , the terminal device  100  accepts distribution of the web page C 10  that does not include the space C 11  at the upper end thereof, and a content C 30  including contents C 31  to C 33  of the same size. It is assumed that each of the contents C 31  to C 33  is a content related to advertisement, similarly to the contents C 21  to C 23 . 
     The respective arrangement areas of the contents C 31  to C 33  are set in the same area on the screen, and the respective visible areas of the contents C 31  to C 33  are arranged so as not to overlap each other. For example,  FIG. 9  is a diagram for explaining a variation of setting of the arrangement area and the visible areas. In the example illustrated in (A) in  FIG. 9 , an arrangement area C 30   a  as the arrangement area of each of the contents C 31  to C 33  is set from the upper end of the web page C 10  so as to have the same size as the display size of each of the contents C 31  to C 33 . 
     Furthermore, in the example illustrated in (A) in  FIG. 9 , visible areas C 31   b  to C 33   b  of the contents C 31  to C 33  are set from the middle of the web page C 10 . Incidentally, the upper end of the visible area C 32   b  is arranged so as to come in contact with the lower end of the visible area C 31   b , and the upper end of the visible area C 33   b  is arranged so as to come in contact with the lower end of the visible area C 32   b.    
     In this case, as illustrated in (B) in  FIG. 9 , the terminal device  100  arranges, in the arrangement area C 30   a , each of the contents C 31  to C 33  in an invisible state, and arranges the web page C 10  behind the contents C 31  to C 33 . In the example illustrated in (B) in  FIG. 9 , dotted lines schematically representing the visible areas C 31   b  to C 33   b  are arranged between the arrangement area C 30   a  and the web page C 10 . Then, as indicated by (C) in  FIG. 9 , the terminal device  100  moves the web page C 10  and each of the visible areas C 31   b  to C 33   b  in accordance with a scroll operation. 
     If the above-described process is performed, the visible area C 31   b  among the visible areas C 31   b  to C 33   b  first overlaps the arrangement area C 30   a . Therefore, the terminal device  100  gradually makes the content C 31  visible from the lower end to the upper end in the arrangement area C 30   a  without moving the content C 31 . 
     Then, in accordance with the movement of the lower end of the visible area C 31   b  and the upper end of the visible area C 32   b  indicated by (D) in  FIG. 9  in the screen upward direction, the terminal device  100  gradually makes the content C 31  invisible from the lower end to the upper end and gradually makes the content C 32  visible from the lower end to the upper end in the arrangement area C 30   a . That is, the terminal device  100  moves the lower end of the display area of the content C 31  in the screen upward direction and moves the upper end of the display area of the content C 32  in the upward direction in the same arrangement area C 30   a.    
     Furthermore, in accordance with the movement of the lower end of the visible area C 32   b  and the upper end of the visible area C 33   b  indicated by (E) in  FIG. 9  in the screen upward direction, the terminal device  100  gradually makes the content C 32  invisible from the lower end to the upper end and gradually makes the content C 33  visible from the lower end to the upper end in the arrangement area C 30   a . That is, the terminal device  100  moves the lower end of the display area of the content C 32  in the screen upward direction and moves the upper end of the display area of the content C 33  in the upward direction in the same arrangement area C 30   a.    
     Then, in accordance with the movement of the lower end of the visible area C 33   b  indicated by (F) in  FIG. 9 , the terminal device  100  gradually makes the content C 33  invisible from the lower end to the upper end in the arrangement area C 30   a , to thereby gradually reduce the display area of the content C 33  from the screen downward direction to the screen upward direction. 
     8-1-2. Example of Display Process for Switching Between Contents 
     Referring back to  FIG. 8 , an example of a display process performed by the terminal device  100  to switch between the contents C 31  to C 33  in accordance with a scroll operation will be described below. In the following description, it is assumed that the upper end of the visible area C 31   b  is arranged at the position of the upper end of the “news  1 ”, and the lower end of the visible area C 31   b  and the upper end of the visible area C 32   b  are arranged at the position of the upper end of the “news  2 ”. It is also assumed that the lower end of the visible area C 32   b  and the upper end of the visible area C 33   b  are arranged at the position of the upper end of the “news  3 ”, and the lower end of the visible area C 33   b  is arranged at the position of the upper end of the “news  4 ”. 
     First, the terminal device  100  accepts distribution of the web page C 10  and the content C 30 . In this case, the terminal device  100  displays the web page C 10  and arranges the content C 20  in the arrangement area C 30   a . Therefore, as illustrated in the first state, the terminal device  100  displays only the web page C 10  in a visible state. 
     If the user performs an upward scroll operation on the web page C 10  with the finger F 10 , the terminal device  100  scrolls the web page C 10  in the screen upward direction. If the upper end of the “news  1 ” contained in the web page C 10  is moved in the screen upward direction relative to the lower end of the arrangement area C 30   a , the terminal device  100  expands the display area of the content C 31  by making the content C 31  visible from the lower end to the upper end in accordance with the position of the upper end of the “news  1 ” as illustrated in the second state. Then, the terminal device  100  gradually expands the display area of the content C 31  in accordance with the upward scroll operation, and makes the entire content C 31  visible as illustrated in the third state. 
     Furthermore, when the entire content C 31  is displayed, and if the upward scroll operation is further performed and the upper end of the “news  2 ” contained in the web page C 10  is moved in the screen upward direction relative to the lower end of the arrangement area C 30   a , the terminal device  100  performs a process as described below. Specifically, as illustrated in the fourth state, the terminal device  100  makes the content C 31  invisible from the lower end to the upper end in accordance with the position of the upper end of the “news  2 ” and simultaneously makes the content C 32  visible from the lower end to the upper end in accordance with the position of the upper end of the “news  2 ”. 
     That is, the terminal device  100  reduces the display area of the content C 31  from the screen downward direction to the upward direction without moving the content C 31 , and expands the display area of the content C 32  from the screen downward direction to the upward direction without moving the content C 32 . Then, the terminal device  100  gradually reduces the display area of the content C 31  and gradually expands the display area of the content C 32  in accordance with the upward scroll operation, to thereby make the entire content C 32  visible as illustrated in the fifth state. 
     Furthermore, if the upward scroll operation is further performed and the upper end of the “news  3 ” contained in the web page C 10  is moved in the screen upward direction relative to the lower end of the arrangement area C 30   a , the terminal device  100  makes the content C 32  invisible from the lower end to the upper end in accordance with the position of the upper end of the “news  3 ” and simultaneously makes the content C 33  visible from the lower end to the upper end in accordance with the position of the upper end of the “news  3 ”. 
     Then, the terminal device  100  gradually reduces the display area of the content C 32  and gradually expands the display area of the content C 33  in accordance with the upward scroll operation, to thereby make the entire content C 33  visible as illustrated in the sixth state. When the entire content C 33  is displayed, and if the upward scroll operation is further performed, the terminal device  100  makes the content C 33  invisible from the lower end to the upper end, to thereby make the content C 30  invisible. 
     As described above, the terminal device  100  can display the contents C 31  to C 33  in a complicated mode such that the content C 31  is switched to the content C 32  and then the content C 32  is switched to the content C 33  from the screen downward direction to the screen upward direction in the same area in accordance with the upward scroll operation performed on the web page C 10 . Therefore, the terminal device  100  can improve the appeal effect of information related to each of the contents C 31  to C 33 . 
     If a downward scroll operation is performed, the terminal device  100  switches the displayed content in order from the contents C 33  to C 31  in accordance with the downward scroll operation as illustrated in the sixth state to the first state. For example, in the example illustrated in  FIG. 9 , if the downward scroll operation is performed, the terminal device  100  gradually makes the content C 33  visible from the upper end to the lower end in the arrangement area C 30   a . Subsequently, the terminal device  100  gradually makes the content C 33  invisible from the upper end to the lower end and gradually makes the content C 32  visible from the upper end to the lower end. Furthermore, the terminal device  100  gradually makes the content C 32  invisible from the upper end to the lower end, gradually makes the content C 31  visible from the upper end to the lower end, and thereafter gradually makes the content C 31  invisible from the upper end to the lower end. 
     8-2. Second Variation 
     The above-described terminal device  100  performs the above-described various display processes by setting the arrangement area and the visible area of each of the contents C 21  to C 23  and C 31  to C 33 . However, the embodiment is not limited to this example. 
     For example,  FIG. 10  is a diagram illustrating a second variation of the display process performed by the terminal device according to the embodiment. In the following description, an example of a process performed by the terminal device  100  to change the display of a content C 40  in the same area will be described in multiple parts, from a first state to a sixth state. 
     For example, as illustrated in  FIG. 10 , the terminal device  100  accepts distribution of the web page C 10  and the content C 40 . In the web page C 10 , the space C 11  for displaying the content C 40  is provided, and the content C 40  is arranged in the space C 11 . The content C 40  is configured with a content C 41  and a content C 42 . 
     The content C 41  includes an area in which characters such as “SALE!” are arranged, and an area in which characters such as “AA shop” are arranged. The content C 42  is a content that has the same display size as that of the area of the content C 41  in which the characters “SALE!” are arranged. In the content C 42 , characters such as “until end of month!” are arranged. 
     In this case, as illustrated in the first state, the terminal device  100  arranges the content C 41  in the space C 11  of the web page C 10  and displays the web page C 10  and the content C 41 . Then, as illustrated in the second state, the terminal device  100  scrolls the web page C 10  and the content C 41  in accordance with an upward scroll operation performed by the user with the finger F 10 . 
     It is assumed that the arrangement area of the content C 42  is arranged at the upper end of the screen, and the visible area of the content C 42  is arranged in the area of the content C 41  in which the characters “AA shop” are arranged In this case, the terminal device  100  moves the content C 41  from the upper end of the screen to the outside of the screen and gradually makes the content C 42  visible from the lower end to the upper end in accordance with the upward scroll operation. 
     Consequently, as illustrated in the third state, the terminal device  100  can implement a complicated display mode such that the terminal device  100  gradually reduces the display area of the characters “SALE!” while moving the characters “SALE!” in the screen upward direction, and expands the display area of the content C 42  from the screen downward direction to the screen upward direction without moving the content C 42 . 
     If the upward scroll operation is further performed, the terminal device  100  makes the entire content C 42  visible as illustrated in the fourth state. If the upward scroll operation is further performed, the terminal device  100  displays the content C 40  so as to move the content C 41  arranged on the back side in the screen upward direction without moving the display area of the content C 42 . 
     If the upward scroll operation is further performed, the terminal device  100  moves the entire content C 41  to the outside of the screen and gradually makes the content C 42  invisible from the lower end to the upper end in accordance with the position of the lower end of the content C 41  without moving the content C 42 . Therefore, the terminal device  100  displays only the web page C 10  as illustrated in the sixth state. 
     8-3. Display Process According to Scroll Direction 
     When an upward scroll operation is performed, the above-described terminal device  100  gradually reduces the display area of the content C 20  from the screen downward direction to the screen upward direction. However, the embodiment is not limited to this example. For example, if a downward scroll operation is performed, the terminal device  100  may gradually reduce the display area of the content C 20  from the screen upward direction to the screen downward direction. Furthermore, if a scroll operation is performed in the horizontal direction from the left side to the right side of the screen, the terminal device  100  may gradually reduce the display area of the content C 20  from the left side to the right side without moving the content C 20 . That is, the terminal device  100  may gradually reduce the display area in accordance with a scroll operation in an arbitrary direction without moving the content C 20 . 
     8-4. Setting of Visible Area 
     The terminal device  100  may employ an arbitrary mode in addition to the modes described above, as long as it is possible to gradually reduce the display areas of the contents C 20  to C 40  in a direction in which a scroll operation is performed without moving the contents C 20  to C 40 . For example, the terminal device  100  may not overlap the visible areas C 21   b  to C 21   b  of the contents C 21  to C 23 , but may set a distance from the lower end of the visible area C 21   a  to the lower end of the visible area C 22   b  and a distance from the lower end of the visible area C 21   b  to the lower end of the visible area C 23   b  to different distances. 
     Furthermore, the terminal device  100  may not arrange the visible areas C 31   b  to C 33   b  of the contents C 31  to C 33  such that the visible areas come in contact with each other. Moreover, the terminal device  100  may set the visible areas such that only parts of the contents C 20  to C 40  are displayed. For example, the terminal device  100  may set a visible area whose display size in the horizontal direction is shorter than that of the content C 20  so that only a part of the content C 20  is displayed. 
     8-5. Visible Area 
     The above-described terminal device  100  sets the visible area in which the contents C 20  to C 40  are made visible. However, the embodiment is not limited to this example. For example, the terminal device  100  may set a range, in which transparency, saturation, brightness, or the like of a range of the contents C 20  to C 40  overlapping the arrangement area is to be changed. Furthermore, if the contents C 20  to C 40  are moving images, the terminal device  100  may set an area in which a playback mode of the moving images, such as playback or stop of the moving images, is controlled. 
     8-6. Arrangement Area 
     The above-described terminal device  100  sets the arrangement areas C 21   a  to C 23   a  and C 30   a  in the upper part of the screen. However, the embodiment is not limited to this example. That is, the terminal device  100  can set the arrangement area in an arbitrary location on the screen. For example, the terminal device  100  can set the arrangement area in an arbitrary location, such as a lower part, a left part, a right part, or a center part, on the screen. Furthermore, the terminal device  100  may arrange a plurality of the arrangement areas C 21   a  of the contents C 21  in the screen. In this case, the terminal device  100  simultaneously changes the display modes of the contents C 21  at a plurality of positions in the screen. 
     8-7. Others 
     The terminal device  100  may perform the display process by appropriately combining the above-described processes. The combination may be arbitrarily set, as a display instruction, by an advertiser when an advertisement content is registered in the advertisement distribution server  20 . The advertisement distribution server  20  generates control information for causing the terminal device  100  to perform the combination of the processes set by the advertiser, and distributes the generated control information to the terminal device  100 . Therefore, the terminal device  100  can combine and perform the arbitrary processes described above in accordance with the setting performed by the advertiser. 
     9. Flow of Process Performed by the Terminal Device  100   
     The flow of a process performed by the terminal device  100  that executes the control information will be described below with reference to  FIG. 11 .  FIG. 11  is a flowchart illustrating an example of the flow of the display process performed by the terminal device according to the embodiment. In the example illustrated in  FIG. 11 , a process will be described in which a content, such as the content C 20 , distributed from the advertisement distribution server  20  is used as an advertisement content. 
     In the example illustrated in  FIG. 11 , the terminal device  100  requests the content distribution server  30  to distribute the web page C 10  in accordance with an operation performed by a user, and receives the web page C 10  from the content distribution server  30  (Step S 101 ). Subsequently, if the distributed web page C 10  includes an acquisition command, the terminal device  100  transmits a distribution request to the advertisement distribution server  20  (Step S 102 ). Then, the terminal device  100  determines whether an advertisement content is received (Step S 103 ). If the terminal device  100  determines that the advertisement content is not received (NO at Step S 103 ), the process at Step S 103  is repeated. 
     If the terminal device  100  receives the advertisement content (YES at Step S 103 ), the terminal device  100  sets an arrangement area of the advertisement content on the screen (Step S 104 ). Furthermore, the terminal device  100  sets a visible area of the advertisement content in the web page C 10  (Step S 105 ). Then, the terminal device  100  displays the web page C 10  and the advertisement content (Step S 106 ). In the process at Step S 106 , only a range of the advertisement content in which the arrangement area and the visible area overlap each other is displayed. For example, in the example illustrated in  FIG. 1 , the terminal device  100  displays the entire content C 20 . 
     Furthermore, the terminal device  100  determines whether a scroll operation is performed (Step S 107 ), and if the scroll operation is performed (YES at Step S 107 ), the terminal device  100  reduces the display area in the scroll direction in accordance with the scroll operation, without moving the advertisement content (Step S 108 ). For example, in the example illustrated in  FIG. 1 , the terminal device  100  gradually reduces the display area of the content C 20  in the screen upward direction without moving the content C 20 . 
     Furthermore, the terminal device  100  determines whether to shift the web page through a process of tapping a link or the like performed by the user (Step S 109 ). If the terminal device  100  determines to shift the web page (YES at Step S 109 ), the terminal device  100  shifts the web page (Step S 110 ), and the process ends. 
     In contrast, if the terminal device  100  determines not to shift the web page (Step S 109 : No), the terminal device  100  performs the process at Step S 107 . If the scroll operation is not performed (NO at Step S 107 ), the terminal device  100  repeats the process at Step S 107 . 
     10. Modifications 
     An example of the display process performed by the terminal device  100  has been described above by using the display modes illustrated in  FIG. 1 ,  FIG. 8 , and  FIG. 10 . However, the embodiment is not limited to this example. Variations of the display process performed by the terminal device  100  will be described below. It is assumed that the display process described below is implemented by, for example, a process performed by the arranging unit  154 , the display unit  155 , and the area control unit  156 . 
     10-1. Mode of Content 
     The above-described terminal device  100  displays a plurality of the contents C 21  to C 23  included in the content C 20 . However, the embodiment is not limited to this example. For example, the contents C 21  to C 23  may be contents related to different advertisements. Furthermore, the terminal device  100  may display the content C 20  configured to provide different contents between when the content C 20  includes the contents C 21  to C 23 , when the content C 20  includes the contents C 21  and C 22 , and when the content C 20  includes only the content C 21 . 
     10-2. Content 
     In the above description, an example has been described in which the terminal device  100  displays the contents C 20  to C 40  related to advertisement. However, the embodiment is not limited to this example. For example, the terminal device  100  may display a content including a character string, a pattern, an image, a moving image, or the like. Furthermore, the terminal device  100  may display the contents C 20  to C 40  including a game or the like, instead of a content related to advertisement, or may display the contents C 20  to C 40  including a so-called playable advertisement. Moreover, the terminal device  100  may display the contents C 20  to C 40  including audio. The character string, the pattern, the image, the moving image, the game, the audio, and the like included in the contents C 20  to C 40  are not limited to those related to advertisement. 
     Furthermore, the content C 20  is not limited to the content related to advertisement. For example, when displaying a game content instead of the web page C 10 , the terminal device  100  may display, as the contents C 20  to C 40 , an auxiliary content, such as a game menu or a game tutorial. Moreover, when displaying an interactive web page generated by a technology using flash, CSS, or the like at the time of execution of the game, the terminal device  100  may display the contents C 20  to C 40  and perform the display process. 
     Furthermore, the terminal device  100  may display the contents C 20  to C 40  together with a content of a social networking service (SNS), a screen of a messenger application, a screen of a camera application, or any other content, and thereafter, may perform the display process as described above. Moreover, the terminal device  100  may display an arbitrary content, such as a game, a map, a music playback screen, or a video playback screen, in addition to the web page C 10 . 
     10-3. Control Information 
     The above-described terminal device  100  performs the above-described display process by using the control information that is distributed from the advertisement distribution server  20  together with the content C 20 . However, the embodiment is not limited to this example. For example, the terminal device  100  receives the above-described control information from the content distribution server  30  together with the web page, and receives a control instruction from the advertisement distribution server  20  together with the content C 20 . Then, the terminal device  100  may execute the control information received from the content distribution server  30 , and perform the display process in accordance with the received control instruction. 
     Furthermore, the terminal device  100  may download, in advance, an application for causing the terminal device  100  to perform a process of displaying the web page C 10 , the above-described display process, and the like, and may implement the above-described processes by executing the application. 
     10-4. Configuration of Apparatus 
     In the above-described embodiment, an example has been described in which the distribution system  1  includes the advertisement distribution server  20  and the content distribution server  30 . However, the advertisement distribution server  20  and the content distribution server  30  may be configured as a single device. In this case, the advertisement distribution server  20  illustrated in  FIG. 3  includes, for example, the content storage unit  32 , the accepting unit  34 , and the distribution unit  35  illustrated in  FIG. 5 . The advertisement distribution server  20 , upon accepting an acquisition request for a web page from the terminal device  100 , distributes an advertisement content and a web page that does not include an acquisition command to the terminal device  100 . 
     In the above-described embodiment, an example has been described in which the advertisement distribution server  20  distributes the content C 20  to the terminal device  100 . However, the content distribution server  30  may acquire the content C 20  from the advertisement distribution server  20 . In this case, the request accepting unit  26  of the advertisement distribution server  20  accepts an acquisition request for the content C 20  from the content distribution server  30 . The advertisement distribution server  20  distributes the content C 20  to the content distribution server  30 . The content distribution server  30  distributes the content C 20  acquired from the advertisement distribution server  20  and a web page that does not include an acquisition command to the terminal device  100 . 
     10-5. Log 
     The terminal device  100  may acquire a log indicating whether the contents C 20  to C 40  are displayed, or a log of a content selected by a user. Furthermore, the terminal device  100  may measure, for each image, a time at which the user performs a selection, in addition to the number of displays or the number of selections of the contents C 20  to C 40 . Moreover, the terminal device  100  may acquire a log indicating whether the contents C 20  to C 40  are displayed from the initial screen or whether the entire contents C 20  to C 30  are hidden. Furthermore, the terminal device  100  may acquire a log indicating whether all of the contents C 20  to C 40  are displayed. Moreover, the terminal device  100  may acquire a log indicating whether the contents C 21  to C 23 , C 31  to C 33 , C 41 , and C 42  are displayed, whether the display areas are reduced, or whether the display areas are expanded, or a log indicating the number of displays or the like. Furthermore, the terminal device  100  may acquire a log indicating the number of times each of the contents C 20  to C 40  is displayed by a single access to the web page C 10 , the number of operations, or the like. 
     For example, if a user ends the display of the web page C 10  without performing a scroll operation, the terminal device  100  may acquire a log indicating that the content C 30  is not viewed. In contrast, if the user performs an upward scroll operation from the initial screen and expands the display area of the content C 31 , the terminal device  100  may acquire a log indicating that the content C 31  is displayed. Furthermore, the terminal device  100  may acquire a log indicating whether the user has selected the contents C 21  to C 23  or whether the user has performed a selection while any of the contents C 21  to C 23  is displayed. 
     The log acquired by the terminal device  100  as described above is useful when the number of impressions or the CTR of the contents C 20  to C 40  is updated, when a charging process for display of the contents C 20  to C 40  is performed, and when an advertising effect is reported to the advertiser. For example, if the content C 20  is in the hidden state and is not displayed again at a later time, it is expected that the user is not interested in the content C 20 . Furthermore, when the contents C 21  to C 23  are displayed a number of times or when the upward scroll operation and the downward scroll operation are performed a number of times, it is expected that the user is interested in the contents C 20  to C 40  and has changed the display mode a number of times. Therefore, a log indicating a change in the display modes of the contents C 20  to C 40  or a log indicating a scroll operation from the initial screen can be an index of whether the user is interested in the contents C 20  to C 40 . Furthermore, the number of times each of the contents C 20  to C 40  is displayed or operated by a single access can be an index of user&#39;s awareness of the advertisement. 
     Therefore, the advertisement distribution server  20  may update the number of impressions or may change the amount of fees by using each of the acquired logs. For example, the advertisement distribution server  20  may change the amount of fees depending on whether a scroll operation in the downward direction is performed from an initial image and the display areas of the contents C 20  to C 40  are expanded or reduced, whether the display modes of the contents C 20  to C 40  are changed, or whether a moving image contained in the contents C 20  to C 40  is reproduced, or depending on the number of the scroll operations or the like. 
     Furthermore, the log acquired by the terminal device  100  may be used to change a content arranged in the landing page. For example, when the user selects the content C 20 , the terminal device  100  may provide a different landing page depending on the size of the display area of the content C 20 , or depending on whether the display mode of the content C 20  is changed to the final state. Moreover, the terminal device  100  may acquire the same landing page, provide, to a server that distributes the landing page, the size of the display area of the content C 20  or a notice indicating whether the display mode of the content C 20  is changed to the final state, and cause the server to change contents arranged in the landing page. 
     10-6. Operation Record of Terminal Device 
     The above-described terminal device  100  may transmit, to the advertisement distribution server  20 , a record indicating the degree of operations that a user has performed on the terminal device  100  with respect to a web page in which the contents C 20  to C 40  according to the embodiment are arranged. Specifically, the terminal device  100  records the contents of scroll operations performed when the contents C 20  to C 40  are arranged, the number of times of the scroll operations, a selection operation performed by the user, positions at which the user selects the contents C 20  to C 40 , display modes of the selected contents C 20  to C 40 , playback status of moving images included in the contents C 20  to C 40 , and the like. 
     Furthermore, the terminal device  100  may record various operations such as the number of selections of the contents C 20  to C 40 , the number of times of reload, an operation of transmitting information for identifying the contents C 20  to C 40  from the terminal device  100  (for example, writing in an SNS or the like), which is performed by the user on the terminal device  100 . The terminal device  100  transmits information on the operation history to the advertisement distribution server  20 . 
     In this case, the advertisement distribution server  20  aggregates information on the operation history distributed from the terminal device  100 , and further acquires information obtained by analyzing the aggregated information. For example, the advertisement distribution server  20  acquires the number of scroll operations performed on the web pages C 10 , the number of executions of the display process, a type of the displayed landing page, a type of a content arranged in the landing page, information on comparison of indices, such as CTRs, of the advertising effect, for both of the case where the contents C 20  to C 40  are distributed together with the control information and the case where the contents C 20  to C 40  are not distributed together with the control information. 
     The history of operations performed on the web page C 10  when the contents C 20  to C 40  are distributed together with the control information may be used as an index of the advertising effect. That is, in the web page in which the contents C 20  to C 40  including the control information according to the embodiment are displayed, not only the fact that a user clicks the contents C 20  to C 40  and a web page (landing page) linked from the contents C 20  to C 40  is displayed, but also the operation history itself indicating the number of operations performed by the user on the web page C 10  (that is, the number of times that the user changes the display mode of the screen) may be used as an index of the user&#39;s interest in the contents C 20  to C 40 . 
     For example, when a user performs an upward scroll operation from the initial screen, the advertisement distribution server  20  compares the number of times each of the contents C 21  to C 23 , C 31  to C 33 , C 40 , and C 41  is displayed or a time during which each of the contents C 21  to C 23 , C 31  to C 33 , C 40 , and C 41  is displayed, so that it is possible to provide an index indicating the degree of interest in information expected to be broadly conveyed by the contents C 20  to C 40  when the contents C 20  to C 40  with the control information according to the embodiment are displayed, that is, it is possible to provide an index indicating the degree of interest in the advertisement. 
     Therefore, by transmitting the information on the operation history of the terminal device  100  to the advertiser terminal  10 , the advertisement distribution server  20  can provide a report indicating the index of the advertising effect of the web page C 10  in which the contents C 20  to C 40  according to the embodiment are displayed. The advertisement distribution server  20  may directly transmit the information or the log on the operation history of the terminal device  100  to the advertiser terminal  10 . 
     Consequently, the advertisement distribution server  20  can provide an advertiser with indication of how the display modes of the contents C 20  to C 40  with the control information according to the embodiment are useful in the terminal device  100 . 
     10-7. Others 
     Of the processes described in the embodiment, all or part of a process described as being performed automatically may also be performed manually. Alternatively, all or part of a process described as being performed manually may also be performed automatically by known methods. In addition, the processing procedures, specific names, and information including various kinds of data and parameters illustrated in the above-described document and drawings may be arbitrarily changed unless otherwise specified. For example, various kinds of information illustrated in the drawings are not limited to the information illustrated in the drawings. 
     The components of the apparatuses illustrated in the drawings are functionally conceptual and need not necessarily be physically configured in the manner illustrated in the drawings. In other words, specific forms of distribution and integration of the apparatuses are not limited to those illustrated in the drawings, and all or part of the apparatuses may be functionally or physically distributed or integrated in arbitrary units depending on various loads or use conditions. For example, the requesting unit  151  and the operation control unit  152  illustrated in  FIG. 6  may be integrated with each other. 
     Furthermore, the embodiments described above may be combined appropriately as long as the processes do not conflict with each other. 
     10-8. Program 
     The terminal device  100 , the advertisement distribution server  20 , and the content distribution server  30  according to the above-described embodiment are implemented by, for example, a computer  1000  with a configuration as illustrated in  FIG. 12 . In the following, a description will be given by using the advertisement distribution server  20  as an example.  FIG. 12  is a diagram illustrating an example of a hardware configuration of a computer that implements the functions of the advertisement distribution server. The computer  1000  includes a CPU  1100 , a RAM  1200 , a ROM  1300 , an HDD  1400 , a communication interface (I/F)  1500 , an input/output I/F  1600 , and a media I/F  1700 . 
     The CPU  1100  operates based on a program stored in the ROM  1300  or the HDD  1400 , and controls each of units. The ROM  1300  stores therein a boot program executed by the CPU  1100  when the computer  1000  is activated, a program that depends on the hardware of the computer  1000 , and the like. 
     The HDD  1400  stores therein a program executed by the CPU  1100 , data used by the program, and the like. The communication I/F  1500  receives data from other devices via the network N, sends the data to the CPU  1100 , and transmits data generated by the CPU  1100  to other devices. 
     The CPU  1100  controls an output device, such as a display or a printer, an input device, such as a keyboard or a mouse, and the like via the input/output I/F  1600 . The CPU  1100  acquires data from the input device via the input/output I/F  1600 . The CPU  1100  outputs generated data to the output device via the input/output I/F  1600 . 
     The media I/F  1700  reads a program or data stored in a recording medium  1800 , and provides the program or the data to the CPU  1100  via the RAM  1200 . The CPU  1100  loads the program onto the RAM  1200  from the recording medium  1800  via the media I/F  1700 , and executes the loaded program. The recording medium  1800  may be, for example, an optical recording medium such as a digital versatile disk (DVD) or a phase change rewritable disk (PD), a magneto-optical recording medium such as a magneto-optical disk (MO), a tape medium, a magnetic recording medium, a semiconductor memory, or the like. 
     For example, when the computer  1000  functions as the advertisement distribution server  20  according to the embodiment, the CPU  1100  of the computer  1000  implements the functions of the control unit  23  by executing the program loaded on the RAM  1200 . Furthermore, the HDD  1400  stores therein data stored in the storage unit  22 , that is, the advertisement database  24 . While the CPU  1100  of the computer  1000  reads the program from the recording medium  1800  and executes the program, the program may be acquired from other devices as another example. 
     When the computer  1000  functions as the terminal device  100  according to the embodiment, the CPU  1100  of the computer  1000  implements the functions of the control unit  150  by executing the program loaded on the RAM  1200 . 
     When the computer  1000  functions as the content distribution server  30  according to the embodiment, the CPU  1100  of the computer  1000  implements the functions of the control unit  33  by executing the program loaded on the RAM  1200 . The HDD  1400  stores therein data in the content storage unit  32 . 
     11. Advantageous Effects 
     As described above, the terminal device  100  displays the web page C 10  as an example of a first content and the content C 20  as an example of a second content. If an upward scroll operation is performed, the terminal device  100  reduces the display area of the content C 20  in the screen upward direction without moving the content C 20 , to thereby expand an area in which the web page C 10  is displayed. 
     Therefore, if a user continues the upward scroll operation, the terminal device  100  makes the content C 20  invisible and expands the display area of the web page C 10 , so that it is possible to prevent the user from getting a negative impression of the content C 20  and make the user aware of the content C 20 . Consequently, the terminal device  100  can cause the content C 20  to attract attention of the user who is interested in the content C 20 , and improve the appeal of the information related to the content C 20 . 
     More specifically, when the content C 20  related to advertisement is displayed, the terminal device  100  can attract interest of the user in the content C 20  related to advertisement, so that it is possible to improve the appeal of the information expected to be conveyed by the content C 20 , that is, the appeal of an advertisement content, and improve the advertising effect. 
     Furthermore, the terminal device  100  moves the lower end of the display area of the content C 20  in the screen upward direction in accordance with an upward scroll operation performed on the web page C 10 . Therefore, the terminal device  100  hides the content C 20  in a mode such that the lower end of the content C 20  is gradually moved in the upward direction. Consequently, it is possible to attract interest of the user in the content C 20 . 
     Moreover, the terminal device  100  arranges a plurality of the contents C 21  to C 23  next to one another and separately reduces the display area of each of the contents C 21  to C 23  in accordance with a scroll operation. Therefore, the terminal device  100  can attract interest of the user in each of the contents C 21  to C 23  while preventing the user from getting a negative impression of the contents C 21  to C 23 . 
     Furthermore, the terminal device  100  reduces the respective display areas of the contents C 21  to C 23  at different timings, and hides the contents C 21  to C 23  in a complicated mode such that the contents C 21  to C 23  are gradually reduced from the lower ends thereof. Therefore, it is possible to improve the appeal effect of the information related to the content C 20  with respect to the user. 
     For example, the terminal device  100  gradually reduces the display areas in order of the content C 23 , the content C 22 , and the content C 21  in accordance with a scroll operation. Therefore, the terminal device  100  can gradually reduce the display mode of the content C 20  including the contents C 21  to C 23  in accordance with the scroll operation. 
     If the above-described display process is performed, the terminal device  100  can improve the appeal effect of the information related to the content C 20  with respect to the user. For example, if the content C 20  is displayed as a single content, the terminal device  100  continues to display the content C 20  on the screen or hides the content C 20  in accordance with the scroll operation. However, the terminal device  100  displays a plurality of the contents C 21  to C 23  and gradually reduces the respective display areas of the contents C 21  to C 23  at different timings in accordance with the scroll operation, so that the content C 20  is gradually hidden. Therefore, for example, when the terminal device  100  displays a content or the like whose display size in the vertical direction is long, the terminal device  100  displays the entire content and also gradually reduces the display area in accordance with a scroll operation. Consequently, it is possible to prevent the user from getting a negative impression of the content and improve the appeal effect of the information related to the content. 
     Moreover, the terminal device  100  arranges the content C 20 , which is another example of the second content, in an invisible state in the screen, and if a scroll operation is performed while the content C 30  is in the invisible state, the terminal device  100  expands the display area of the content C 30  in a direction in which the scroll operation is performed, without moving the content C 30 , to thereby expand the area in which the web page C 10  is displayed. 
     Therefore, the terminal device  100  displays only the web page C 10  in the initial screen, and thereafter displays the content C 30  in accordance with a scroll operation, so that it is possible to prevent a reduction in the visibility of the web page C 10  in the initial screen and make the user aware of the content C 30 . Consequently, the terminal device  100  can improve the appeal effect of the information related to the content C 30 . 
     Furthermore, if an upward scroll operation is performed on the web page C 10  while the content C 30  is in the invisible state, the terminal device  100  moves the upper end of the display area of the content C 30  in the screen upward direction. Therefore, the terminal device  100  can implement a complicated mode such that the terminal device  100  gradually displays the content C 30  from the lower end in accordance with the upward scroll operation without moving the content C 30 . Consequently, the terminal device  100  can improve the appeal effect of the information related to the content C 30 . 
     Moreover, for example, the terminal device  100  arranges the content C 32  with the same display size as the content C 31  that is an example of the second content, at the same position and in an invisible state. Then, the terminal device  100  reduces the display area of the content C 31  in a direction in which the scroll operation is performed, and simultaneously expands the display area of the content C 32  in the direction in which the scroll operation is performed, without moving the content C 32 . 
     Therefore, the terminal device  100  can switch between the contents C 31  and C 32  in a complicated mode such that the content C 31  is gradually switched to the content C 32  from the lower end to the upper end in accordance with upward scroll. Consequently, the terminal device  100  can improve the appeal effect of the information related to the content C 30 . 
     Furthermore, if a scroll operation is performed while the entire content C 31  is displayed, the terminal device  100  reduces the display area of the content C 31  in a direction in which the scroll operation is performed, and simultaneously expands the display area of the content C 32  in the direction in which the scroll operation is performed, without moving the content C 32 . Therefore, the terminal device  100  can cause the user to view the entire content C 31 . 
     Moreover, if a scroll operation is performed while the entire content C 33  as an example of the third content is displayed, the terminal device  100  reduces the display area of the content C 33  in a direction in which the scroll operation is performed, to thereby expand the area in which the web page C 10  is displayed. Therefore, the terminal device  100  can attract interest of the user to each of the contents C 31  to C 33  while preventing the user from getting a negative impression of each of the contents C 31  to C 33 . 
     Furthermore, the advertisement distribution server  20  distributes the control information to the terminal device  100 . The control information causes the terminal device  100  to perform a process of displaying the web page C 10  and the content C 20 , and if an upward scroll operation is performed, causes the terminal device  100  to perform a process of reducing the display area of the content C 20  in the screen upward direction without moving the content C 20 , to thereby expand the area in which the web page C 10  is displayed. Therefore, the advertisement distribution server  20  can attract interest of the user in each of the contents C 21  to C 23  while preventing the user from getting a negative impression of each of the contents C 21  to C 23 . 
     While the embodiments of the present invention have been described above in detail, these embodiments are mere examples, and the present invention may be embodied in various different forms including modifications based on the knowledge of those skilled in the art, other than the above-described embodiments. 
     Furthermore, “a unit” recited in the claims may be replaced with “a section, a module, or a means” or “a circuit”. For example, the distribution unit may be replaced with a distribution means or a distribution circuit. 
     According to an embodiment of the present invention, it is possible to improve an appeal effect of information related to a content. 
     Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.