Patent Publication Number: US-7590691-B2

Title: Indirect subscriptions to top N lists of content feeds

Description:
RELATED APPLICATIONS 
   This application is related to the following U.S. patent applications, which are incorporated by reference herein in their entirety: 
   U.S. patent application Ser. No. 11,246,596, titled “Personalized Content Feed Suggestions Page,” filed Oct. 7, 2005; 
   U.S. patent application Ser. No. 11/246,657, titled “Content Feed User Interface with Gallery Display of Same-Type Items,” filed Oct. 7, 2005; and 
   U.S. patent application Ser. No. 11/246,597, titled “Indirect Subscriptions to A User&#39;s Selected Content Feed Items,” filed Oct. 7, 2005. 
   TECHNICAL FIELD 
   The disclosed embodiments relate generally to content syndication, and more particularly, to providing indirect subscriptions to feed content. 
   BACKGROUND 
   Content syndication is growing in popularity as a way to distribute frequently updated information, such as news and blog postings, on the Internet. Using content syndication formats such as Really Simple Syndication (RSS), content providers can include content and/or links to such in a content feed. Users may subscribe to these content feeds using an application known as a reader or aggregator. When the content feed is updated with new content items, the new content items are reflected in the user&#39;s reader. 
   A passive user may wish to avoid managing her content feed subscriptions. One way is to adopt another user&#39;s content feed subscriptions as her own, thus delegating the responsibility of selecting content feeds for subscription to that another user. A second user may export his list of content feed subscriptions to a file. The first user can import the file into her aggregator application and subscribe to the content feeds included in the file. However, this still requires some subscription management on the part of the first user, since she is still responsible for unsubscribing from content feeds to which she no longer wishes to subscribe. 
   Accordingly, there is a need for a more efficient manner of subscribing to feed content. 
   SUMMARY OF EMBODIMENTS 
   In accordance with some embodiments, a method of subscribing to content includes subscribing a user to a content feed group that includes a set of content feeds; presenting to the user a first plurality of content items in accordance with the content feed group; and after a change to the content feed group, presenting to the user a second plurality of content items in accordance with the changed content feed group. 
   In accordance with some embodiments, the aforementioned operations may be performed by a system having memory, one or more processors, and one or more modules stored in the memory and configured for execution by the processors. 
   In accordance with some embodiments, instructions for the aforementioned operations may be included in a computer program product for use in conjunction with a computer system. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram illustrating a content feed aggregation system in accordance with some embodiments. 
       FIG. 2  is a flow diagram illustrating a process for presenting to a user content selected by another user, in accordance with some embodiments. 
       FIGS. 3A-3B  are flow diagrams illustrating a process for presenting to a user content feeds selected by another user, in accordance with some embodiments. 
       FIG. 4  is a flow diagram illustrating a process for presenting to a user content feeds selected according to predefined criteria, in accordance with some embodiments. 
       FIG. 5  is a block diagram illustrating a client computer in accordance with some embodiments. 
       FIG. 6  is a block diagram illustrating a server computer in accordance with some embodiments. 
       FIG. 7  is a diagram illustrating a feed reader user interface in accordance with some embodiments. 
       FIG. 8  is a diagram illustrating a labels page in accordance with some embodiments. 
       FIG. 9  is a diagram illustrating an active subscriptions page in accordance with some embodiments. 
       FIG. 10  is a diagram illustrating an available subscriptions page in accordance with some embodiments. 
       FIG. 11  is a diagram illustrating a data structure for feed content items, in accordance with some embodiments. 
   

   Like reference numerals refer to corresponding parts throughout the drawings. 
   DESCRIPTION OF EMBODIMENTS 
   A content feed aggregation system may provide for indirect subscriptions. Rather than subscribing directly to content feeds (or primary feeds), a user can subscribe to a group of content items or a group of content feeds selected by another user or according to predefined criteria. The selected items or feeds are “repackaged” into a “secondary” content feed, to which the user may subscribe. The content items included in the secondary feed may change as the selection of content items or content feeds changes and the content items presented by the user as part of the subscription to the secondary feed changes along in accordance with the changed selection. 
     FIG. 1  is a block diagram illustrating a content feed aggregation system in accordance with some embodiments. The content feed aggregation system  100  includes a server system  104 . The server system  104  is coupled to one or more client systems  102  and to one or more hosts  120  (or “feed sources”) by a network  106 . The network  106  may be any suitable wired and/or wireless network and may include a local area network (LAN), wide area network (WAN), the Internet, and so forth. 
   The server system  104  accesses content feeds from the feed sources  120 . The server system  104  includes a server  108  and a database  110 . Server  108  serves as a front-end for the server system  104 . Server  108  retrieves the content feeds from the feed sources  120 , and also provides an interface between the server system  104  and the client systems  102 . In some embodiments, the functions of server  108  may be divided or allocated among two or more servers. 
   The server system  104  stores content items in the content feeds in the database  110 . In some embodiments, the database  110  stores both metadata (e.g., title, description, URL, date/time, and possibly other metadata) and the content of each content item. However, in some other embodiments, the database  10  stores the metadata but not the content for each content item. The database  10  also stores user feed information  112  for a plurality of users. The user feed information for a particular user identifies content feed subscriptions, as well as sources, filters, and read states for that particular user. That is, user feed information associated with a user identifies the content feeds to which the user has subscribed, any filters the user has defined for the feeds, any labels the user has associated with individual feed items, and an indication of whether each feed item has been marked as “read” by the user. 
   It should be appreciated that the server system  104 , including the server  108  and the database  10 , may be implemented as a distributed system of multiple computers. However, for convenience of explanation, the server system  104  is described below as being implemented on a single computer, which can be considered a single logical system. 
   A content feed (or channel) is a resource or service that provides a list of content items that are present, recently added, or recently updated at a feed source  120 . A content item in a content feed may include the content associated with the item itself (the actual content that the content item specifies), a title and/or a description of the content, a locator (e.g., URL) of the content, or any combination thereof. For example, if the content item identifies a text article, the content item may include the article itself inline, along with the title and locator. Alternatively, a content item may include the title, description and locator, but not the article content. Thus, some content items may include the content associated with those items, while others contain links to the associated content but not the full content of the items. A content item may also include additional metadata that provides additional information about the content. The full version of the content may be any machine-readable data, including but not limited to web pages, images, digital audio, digital video, Portable Document Format (PDF) documents, and so forth. 
   In some embodiments, a content feed is specified using a content syndication format, such as RSS. RSS is an acronym that stands for “rich site summary,” “RDF site summary,” or “Really Simple Syndication.” “RSS” may refer to any of a family of formats based on the Extensible Markup Language (XML) for specifying a content feed and content items included in the feed. In some other embodiments, other content syndication formats, such as the Atom syndication format or the VCALENDAR calendar format, may be used to specify content feeds. 
   Further information regarding the RSS syndication format known as “Really Simple Syndication” is disclosed in the  RSS  2.0  Specification  by D. Winer, which is hereby incorporated by reference herein in its entirety. M. Nottingham et al. disclose further information regarding the Atom syndication format in  The Atom Syndication Format , which is hereby incorporated by reference herein in its entirety. 
   A user interfaces with the server system  104  and views content items at a client system or device  102  (hereinafter called the client system for ease of reference). The client system  102  includes a computer  118  or computer controlled device, such as a personal digital assistant, cellular telephone or the like (hereinafter called the client system for ease of reference). The computer  118  typically includes one or more processors (not shown); memory, which may include volatile memory (not shown) and non-volatile memory such as a hard disk drive  119 ; and a display  114 . The computer  118  may also have input devices such as a keyboard and a mouse (not shown). 
   In some embodiments, a user may interact with the server system  104  via a feed reader user interface  116  that may be presented on the display  114 . The user may create a list of feed subscriptions via the feed reader user interface  116 . In some embodiments, using the feed reader user interface  116 , the user may also create filters or labels to be applied to content feeds and/or content items, and modify the read states of content feeds and/or content items. The feed reader user interface transmits a list of content feed subscriptions, or modifications to a list of content feed subscriptions, to the server system  104  for storage at the database  110 . The feed reader user interface  116  presents content items stored at the database  110  to the user based on the user&#39;s list of content feed subscriptions. That is, feed reader user interface  116  presents to the user content items specified in the content feeds to which the user has subscribed. A user may view the full version of the content of a content item in the feed reader user interface  116  by selecting it (e.g., by clicking on it with a mouse pointer). In some embodiments, a copy of the user&#39;s list of content feed subscriptions and copies of the presented content items may be cached locally at the client system  102 . 
   In some embodiments, the feed reader user interface  116  may be a web-based user interface. That is, the feed reader user interface  116  includes a plurality of web pages. The web pages may be written in the Hypertext Markup Language (HTML), Extensible Markup Language (XML), or any other suitable language for preparing web pages, and may include one or more scripts for interfacing with the server system  104 . The user may subscribe to content feeds, view content items, and otherwise interact with the server system  104  by interacting with the web pages of the feed reader user interface  116 . In other words, the server system  104 , including the feed reader user interface  116 , provides a web-based content aggregation service. The server system  104  aggregates and stores content items in accordance with the user&#39;s content feed subscriptions. In some embodiments, the server system  104  can also apply filters or labels, or change the read states of content items in accordance with user actions or instructions. When the user accesses the feed reader user interface  116 , the content items are presented to the user via the feed reader user interface  116 . 
   In some other embodiments, the feed reader user interface  116  may be a part of a standalone application that is run on the client system  102 . The standalone application may interface with the servers system  104  via an application programming interface (API). 
     FIG. 2  is a flow diagram illustrating a process  200  for presenting to a user content selected by another user, in accordance with some embodiments. At a first client (hereinafter “Client A” for convenience), a first user (hereinafter “User A” for convenience) applies a tag (or “label”) to one or more content items in the feed reader user interface  116  ( FIG. 1 ) ( 202 ). The content items need not be all from the same content feed; the content items may be from any number of content feeds to which User A is subscribed. The tag may be a default tag predefined by the system or a tag created and defined by User A. In some embodiments, the user may define a filter or rule to automatically tag (or “label”) items on her behalf. For example, the user may define a rule to apply a “Sports” tag to all content items with at least one of the keywords “baseball,” “football,” “basketball,” “hockey,” and “soccer.” 
   For purposes of this description, the words “tag” and “label,” whether used as a noun or as a verb, are interchangeable. 
   At the server, the tag is applied to the one or more content items, which are stored in the database  110  ( FIG. 1 ), in accordance with the application of the tag to the content items by User A ( 204 ). In some embodiments, the tag is applied at the server by associating the content items with the tag in the database  110 . The tagged content items are associated with a content feed that includes the tagged content items (hereafter the “secondary feed”) ( 206 ). In other words, the secondary feed is a content feed generated from tagged content items. In some embodiments, the tagged content items are aggregated and listed in a content feed document written according to a content syndication format such as RSS or Atom. The content feed document is the secondary feed. In some embodiments, the secondary feed is associated with the user who applied the tag (User A in this case), as well as being associated with the tag. 
   The secondary feed is made available for subscription by other users ( 208 ). In some embodiments, the secondary feed is added to a list, which is accessible to other users, of available content feed subscriptions. Other users may view the list and select the secondary feed for subscription. In some embodiments, the availability of the secondary feed is limited to users selected or approved by Client A. In some embodiments, the set of users to whom the secondary feed is available may be limited, at Client A&#39;s election, to users with whom Client A has a mutual presence subscription in an instant messaging application or service. 
   At a second client (hereinafter “Client B” for convenience), a second user (hereinafter “User B” for convenience) subscribes to the secondary feed ( 210 ). The content items in the secondary feed (i.e., the content items tagged by User A) are presented to the user ( 212 ). In some embodiments, items already viewed by User B in the past may be hidden from the user and thus the content items actually presented may be a subset of the items in the secondary feed. 
   After the subscription to the secondary feed by User B, User A may choose to apply the tag to additional content items or remove the tag from one or more content items to which the tags were applied. The content items in the secondary feed are changed in accordance with the user&#39;s tagging changes. That is, the additional items tagged by User A are added to the secondary feed and the content items from which the tag was removed are removed from the secondary feed. In some embodiments, the changes to the secondary feed are also reflected in the presentation of content items to User B. 
     FIGS. 3A-3B  are flow diagrams illustrating a process for presenting to a user content feeds selected by another user, in accordance with some embodiments. Attention is now directed to process  300  in  FIG. 3A , which is similar to process  200  in  FIG. 2 . At Client A, User A applies a tag (or “label”) to one or more content feeds to which User A is subscribed in the feed reader user interface  116  ( FIG. 1 ) ( 302 ). The tag may be a default tag predefined by the system or a tag created and defined by User A. Application of the tag to the content feeds creates, at least conceptually, a content feed group that includes a set of one or more content feeds. The content feed group is herein called a secondary feed. 
   At the server, the tag is applied to content items in the set of content feeds tagged by the user, in accordance with the application of the tag to the content feeds by User A ( 304 ). In some embodiments, the tag is applied at the server by associating the content items with the tag in the database  110 . The tagged content items are associated with a secondary feed ( 306 ), similar to operation  206  ( FIG. 2 ). In some embodiments, the tagged content items are aggregated and listed in a content feed document written according to a content syndication format such as RSS or Atom. The content feed document is the secondary feed. The secondary feed represents the content feed group; the secondary feed includes the content items included in the content feeds that belong to the content feed group. In some embodiments, the secondary feed is associated with the user who applied the tag (User A in this case), as well as being associated with the tag. 
   The secondary feed is made available for subscription by other users ( 308 ). In some embodiments, the secondary feed is added to a list, which is accessible to other users, of available content feed subscriptions. Other users may view the list and select the secondary feed for subscription. In some embodiments, as in process  200  ( FIG. 2 ), the availability of the secondary feed is limited to users selected or approved by Client A. In some embodiments, the set of users to whom the secondary feed is available may be limited, at Client A&#39;s election, to users with whom Client A has a mutual presence subscription in an instant messaging application or service. 
   At Client B, User B subscribes to the secondary feed ( 310 ). User B, by subscribing to the secondary feed, subscribes to the content feed group represented by the secondary feed. The content items in the secondary feed (i.e., the content items in the content feeds tagged by User A and belonging to the content feed group) are presented to the user ( 312 ). In some embodiments, items already viewed by User B in the past may be omitted and thus the content items actually presented may be a subset of the items in the tagged content feed. 
   Attention is now directed to  FIG. 3B , which illustrates a process  320  of presenting to a user a changed selection of content feeds. After the process  300 , User A may apply the same tag to additional content feeds and/or remove the tag from one or more content feeds to which the tag has been applied. The content items presented to User B may change in accordance to the tagging changes made by User. A. 
   User A changes the tagging on the content feeds ( 322 ). User A applies the same tag to additional content feeds and/or removes the tag from one or more content feeds to which the tag has been applied. This changes the content feed group by adding and removing content feeds from the set of content feeds included in the content feed group. 
   At the server, the tagging of the content items is changed in accordance with the tagging changes made by User A ( 324 ). The content items that are tagged are associated with the secondary feed ( 326 ), as in operation  306  ( FIG. 3A ). The tag is applied to content items in the additional content feeds that were newly tagged by User A. In some embodiments, the tag is applied only to content items, in the additional content feeds, dated after the application of the tag to the additional content feeds. In other words, only content items from the additional content feeds dated after the secondary feed update are added to the secondary feed. In some other embodiments, the tag is applied to all of the content items in the additional content feeds. That is, all of the content items in the newly tagged content feeds are added to the secondary feed. 
   For the content feeds from which the tag was removed, in some embodiments, content items dated after the removal of the tag from the content feeds are not tagged. In other words, the tag is not applied to content items in a content feed from which the tag was removed, as of the time of the removal of the tag from the content feed. Thus, while content items dated after the content feed was removed from the content feed group are not included in the secondary feed, items dated before the removal may remain in the secondary feed. In some other embodiments, the tag is removed from all of the content items in the content feed from which the tag was removed. As a result, all of the content items in the removed content feed are removed from the secondary feed. 
   The content items in the secondary feed are presented to User B ( 328 ), assuming that the subscription to the tagged content feed is still active since the process  300  The presented content items include content items added to the secondary feed as a result of adding a content feed to the content feed group and may exclude content items removed from the secondary feed as a result of removing a content feed from the content feed group. As described above, content items read by the user may be omitted from the presentation. 
   While the processes  200 ,  300 , and  320  are described as involving two users on distinct clients, it should be appreciated that the processes described above may involve two or more users using a multi-user computer, such as a computer that has user accounts and profiles for each user of the computer, but using the content aggregation service at different times. 
     FIG. 4  is a flow diagram illustrating a process for presenting to a user content feeds selected according to predefined criteria, in accordance with some embodiments. In some embodiments, rules, filters, or criteria for tagging content feeds may be predefined. These rules, filters, or criteria may be used to automatically generate secondary feeds to which users may subscribe. For example, a rule may be one for tagging the five most subscribed-to content feeds. This rule would generate a secondary feed that includes content items from the top five content feeds in terms of overall subscriptions. As subscription numbers change, the content feeds in the top five content feeds may change. The list of content items in the tagged content feed changes to reflect changes in the list of top five content feeds. 
   A tagging criterion, rule, or filter is identified ( 402 ). A tag is applied to content items in content feeds satisfying the tagging criteria/rule/filter ( 404 ). For example, using the above example of the rule for tagging the top five subscribed feeds, content items in the five most subscribed-to content feeds are tagged. The tagging criteria/rule/filter defines a content feed group that includes the content feeds that satisfies the criteria/rule/filter. The tagged content items are associated with a secondary feed that represents the content feed group defined by the criteria/rule/filter ( 406 ), similar to operations  206  ( FIG. 2) and 306  ( FIG. 2 ). The secondary feed is made available for subscription by users ( 408 ), as in operations  208  ( FIG. 2) and 308  ( FIG. 3 ). 
   A user at a client subscribes to the secondary feed ( 410 ). It is noted that subscription operation  410  may occur before or after operations  402 - 408 . The content items in the secondary feed are presented to the user ( 412 ). As described above, content items already viewed by the user may be omitted from the presentation. 
   Just as a user can add or remove tags from content feeds, the same can be done by the predefined tagging criteria, rule, or filter. Taking again the example of the rule which tags the five most subscribed content feeds, the list of the top five subscribed-to content feeds may change over time. As that list changes, content feeds are automatically added and removed from the content feed group. As a result, content items may be added and removed from the secondary feed, similar to the adding and removal of content items from the secondary feed in process  320 . 
   Furthermore, tagging criteria or rules or filters for tagging individual content items from any number of content feeds, similar to a user&#39;s tagging of content items from any number of content feeds (as described in relation to process  200 ), may be created. For example, a rule for tagging content items having a particular keyword may be created. Such a rule may be particularly useful for aggregating content items related to a newsworthy person, place, or event. 
   As described above, a secondary feed and content items included in the secondary feed may be associated with a tag and with the user who applied the tag. More precisely, the secondary feed may be associated with a user-tag pair. In some embodiments, the content aggregation service may include privacy options that control whether such secondary feeds may be revealed to other users at large (e.g., in a list of available subscriptions) and thus available to other users for subscription, or revealed only to the user with whom the secondary feed is associated. In some embodiments, another privacy setting is to limit visibility of a secondary feed to a set of users selected or approved by the user who created the secondary feed. By setting the privacy options, a user may control the sharing of her tagged content items or content feeds with other users. In some embodiments, the privacy options are set on a per-tag basis. In some embodiments, the default privacy setting for each tag is a maximum privacy setting. As a result, a secondary feed associated with a tag applied by a first user is made available to other users only when the first user has selected less restrictive privacy settings than the default privacy setting. 
   In some embodiments, the predefined criteria or rules or filters for tagging content feeds or content items may be implemented logically, at the server, as an “imaginary user” tagging content items or content feeds as if it is a real user of the service. That is, an imaginary user representing the criteria/rule/filter is created and associated data is stored at the server. In some embodiments, the privacy options for the imaginary user are always set to share its secondary feed with other users at large. The secondary feed generated as a result of the tagging criteria/rule/filter is associated with the imaginary user. By implementing the tagging criteria/rule/filter as an imaginary user, data in the content aggregation service may share a uniform structure, making data storage more efficient. 
   By allowing tagging of content items and content feeds and generating secondary feeds from them, the content aggregation service enables indirect subscriptions. A user may tag content items or content feeds of interest to her. A user may subscribe to a secondary feed, whether generated by another user or by a predefined rule for tagging items or feeds, to delegate responsibility of subscribing to content to another user or entity, and/or to get content that may be of interest or noteworthy for some reason (e.g., for being popular in terms of having many subscribers, for being on-topic with regard to a newsworthy person, and so forth). 
     FIG. 5  is a block diagram illustrating a client computer in accordance with some embodiments. The client computer  500  typically includes one or more processing units (CPU&#39;s)  502 , one or more network or other communications interfaces  506 , memory  504 , and one or more communication buses  514  for interconnecting these components. The client computer  500  may also include a user interface  508  comprising a display device  510  and a keyboard and/or mouse (or some other pointing device)  512 . Memory  504  includes high-speed random access memory, such as DRAM, SRAM, DDR RAM or other random access solid state memory devices; and may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. Memory  504  may optionally include one or more storage devices remotely located from the CPU(s)  502 . In some embodiments, memory  504  stores the following programs, modules and data structures, or a subset thereof:
         an operating system  516  that includes procedures for handling various basic system services and for performing hardware dependent tasks;   a network communication module  518  that is used for connecting the client system  500  to other computers via the one or more communication network interfaces  506  and one or more communication networks, such as the Internet, other wide area networks, local area networks, metropolitan area networks, and so on; and   a feed reader module  520  for handling content items from content feeds; and   a client application  530 , such as a web browser.       
   The feed reader module  520  includes a content tagging module  522  for tagging content items and content feeds in response to user input. 
   In some embodiments, the feed reader module  520  may be a script-based module, embedded in a web page served from the server system  104  ( FIG. 1 ). The web page may be rendered by a client application  530 , such as a web browser, at the client computer  500 . When the web page is rendered, the feed reader module  520  is executed, thereby providing a web-based interface to the server system  104 . The script-based feed reader module may be written in JavaScript, ECMAScript or any other suitable scripting language. 
   In some other embodiments, the feed reader module  520  may be a standalone application stored in memory  504  of the client computer  500 . The standalone application may include, but is not limited to a feed aggregator application. In further other embodiments, the feed reader module  520  may be an add-on or a plug-in to another application. For, example, the feed reader module  520  may be a plug-in to a web browser application or an email application. 
   In some embodiments, received content items may be cached locally in memory  504 . Similarly, a user&#39;s list of content feed subscriptions may also be cached locally in memory  504 . 
   Each of the above identified elements may be stored in one or more of the previously mentioned memory devices. Each of the above identified modules corresponds to a set of instructions for performing a function described above. The above identified modules or programs (i.e., sets of instructions) need not be implemented as separate software programs, procedures or modules, and thus various subsets of these modules may be combined or otherwise re-arranged in various embodiments. In some embodiments, memory  504  may store a subset of the modules and data structures identified above. Furthermore, memory  504  may store additional modules and data structures not described above. 
     FIG. 6  is a block diagram illustrating a server computer in accordance with some embodiments. The server computer  600  typically includes one or more processing units (CPU&#39;s)  602 , one or more network or other communications interfaces  606 , memory  604 , and one or more communication buses  610  for interconnecting these components. The server system  600  optionally may include a user interface  608 , which may include a display device (not shown), and a keyboard and/or a mouse (not shown). Memory  604  includes computer-readable storage medium such as high-speed random access memory, such as DRAM, SRAM, DDR RAM or other random access solid state memory devices; and may include computer-readable non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. Memory  604  may optionally include one or more computer-readable storage devices remotely located from the CPU(s)  602 . In some embodiments, memory  604  stores the following programs, modules and data structures, or a subset thereof:
         an operating system  612  that includes procedures for handling various basic system services and for performing hardware dependent tasks;   a network communication module  614  that is used for connecting the server system  600  to other computers via the one or more communication network interfaces  606  and one or more communication networks, such as the Internet, other wide area networks, local area networks, metropolitan area networks, and so on;   a feed tracker module  616  for retrieving content items for storage periodically and/or as content feeds are updated;   a feed content provisioning module  617 , for identifying and sending to users content items from the feeds to which they have subscribed;   user data  618 , which includes data for each user of the service;   feed content items  620 , which includes content items from content feeds;   content item tagging module  624  for tagging content items; and   tagging criteria  626 , which includes criteria, rules, or filters for automatically tagging content items.       
   The feed content items  620  include content items  622  that are associated with one or more tags. A content item may be associated with one or more tags. In some embodiments, the feed content items  620  may be stored as a database of content items and tags. 
   The user data  618  includes data for users of the service, such as login information and user preferences. The user data  618  may include subscription lists (not shown), which include lists of users&#39; feed subscriptions. Each user has a corresponding list of content feed subscriptions. 
   The feed content provisioning module  617  identifies and sends content items to a user in accordance with the user&#39;s feed subscriptions. The feed content provisioning module  617  may update the user data  618  to identify content items viewed by the user, so as to avoid sending those same items to the user again. Optionally, for instance in accordance with service features selected by the user, the feed content provisioning module  617  may also update the user data  618  to record other information, such as information identifying content items bookmarked by the user or otherwise marked or selected by the user as being of special interest to the user. 
   Each of the above identified elements may be stored in one or more of the previously mentioned memory devices. Each of the above identified modules corresponds to a set of instructions for performing a function described above. The above identified modules or programs (i.e., sets of instructions) need not be implemented as separate software programs, procedures or modules, and thus various subsets of these modules may be combined or otherwise re-arranged in various embodiments. In some embodiments, memory  604  may store a subset of the modules and data structures identified above. Furthermore, memory  604  may store additional modules and data structures not described above. 
   Although  FIG. 6  shows a “server computer,”  FIG. 6  is intended more as functional description of the various features which may be present in a set of servers than as a structural schematic of the embodiments described herein. In practice, and as recognized by those of ordinary skill in the art, items shown separately could be combined and some items could be separated. For example, some items shown separately in  FIG. 6  could be implemented on single servers and single items could be implemented by one or more servers. 
     FIG. 7  illustrates a feed reader user interface in accordance with some embodiments. The user, via the feed reader user interface  116 , may view, among other things, content items from her subscribed content feeds. The feed reader user interface  116  (hereinafter the “UI”) includes one or more buttons, menus, links, and the like  710  for activating and deactivating various functions and features. 
   The user may view the content items in a “universal view.” The universal view includes a list  702  of content items from all of the user&#39;s subscribed feeds that have new content items not yet viewed by the user. The list  702  may be generated, for example, by the feed content provisioning module  617  of the server computer  600 . In some embodiments, various criteria may be used (by the feed content provisioning module  617 ) to limit the items included in the list  702 , such as publication date and time, and number of items not yet viewed by the user that were published by the same source. For instance, items published more than X (e.g., 7) days ago, may be excluded. In another example, when there are more than Y (e.g., 10) unviewed items from the same source, only the Y most recent unviewed items from the source may be included in the list  702 . 
   The content items  704  shown in the list  702  are interleaved without regard to source. In some embodiments, the list is sorted by publication date and time, for example in reverse chronological order. Also, in some embodiments, the list may show only content items that the user has not viewed. The list presents identifying information for the content items, so that the user can identify a content item she wishes to view and select it. Because the UI  116  may have a finite size and the list may include more items than can fit into the Uí, the UI  116  may display a subset of the content items at a given time and the user may scroll through the list to find other content items. The list may also include an indicator  706  of how many content items are in the list in total. Alternatively, the indicator  706  may indicate the number of content items yet to be viewed. 
   From the list, the user may select a content item. When the user selects an item from the list in the universal view, the UI  116  may display the full version of the content in a viewer region  708 . For example, if the selected content item (indicated by a box with a thick border) includes a link to an article at a news web site or a link to a blog posting, the article or the blog posting, respectively, may be displayed in the viewer region  708 . 
   The UI  116  may also include a labels button  712  that the user may select to open a labels page that allows the user to create, view, edit, and remove tags (hereinafter “labels”). The UI  116  may include a pull-down menu  714 . The user may use the pull-down menu  714  to apply a label to the currently selected content item. 
     FIG. 8  illustrates a labels page in accordance with some embodiments. The labels page  800  includes a list of labels (or “tags”)  802 . The list of labels  802  may include one or more default, system-defined labels such as a star (or a “favorites” label)  802 -A. The list of labels  802  may also include one or more labels created by the user, such as a “Tech” label  802 -B. Links  804  to label editing functions are provided for user-defined labels. The user may select a link  804  corresponding to a particular user-defined label to edit or delete that label. A link  804  to label editing functions is not provided for system-defined labels because such labels may not be edited or deleted by the user. The labels page  800  also includes links  806  for viewing content feeds associated with the label (i.e., the content feeds in the content feed group represented by the label) and links  808  for viewing content items associated with the label (i.e., the content items in the secondary feed associated with the label). Also included are: a button  810  the user may select to create a new label, and a cancel button  812  to cancel out of the labels page  800 . In some embodiments, a label may be a character string or an icon (or symbol) with a corresponding character string. 
     FIG. 9  is a diagram illustrating an active subscriptions page in accordance with some embodiments. The active subscriptions page  900  includes a list  904  of the user&#39;s active subscriptions. The active subscriptions  904  includes content feeds to which the user has subscribed, among which may include content feeds (primary feeds) provided by feed sources  120  ( FIG. 1 ), such as content feed  904 -A, and secondary feeds, such as secondary feed  904 -B. In some embodiments, the name of a secondary feed  904 -B associated with a label applied by a real user (as opposed to an imaginary user, as described above) includes a name of the user who “created” the secondary feed (by labeling one or more content feeds and/or content items) and the character string of the label itself. The subscriptions page  900  also includes labels  902 , if any, associated with the subscribed-to content feeds  904 . Each subscribed-to content feed  904  may have zero or more labels. In some embodiments, even a subscribed-to secondary feed may have zero or more labels. 
   The subscriptions page may further include links  906  to view content items associated with the corresponding subscribed-to content feed  904 , pull-down menus  908  to add labels to the subscribed-to content feeds  904 , and links  910  to unsubscribe from any of the subscribed-to content feeds  904 . A cancel button  912  may be selected by the user to cancel out of the subscriptions page  900 . 
     FIG. 10  is a diagram illustrating an available subscriptions page in accordance with some embodiments. The available subscriptions page  1000  lists content feeds to which the user has not subscribed and may subscribe. The available subscriptions page  1000  includes the list of available content feeds  1002  and links  1004  that the user may select to subscribe to the corresponding content feed. The available content feeds in the list  1002  may include any number of content feeds from feed sources  120  ( FIG. 1 ) and any number of secondary feeds. A cancel button  1006  for canceling out of the available subscriptions page  1000  may be included. In some embodiments, a search box  1008  and a search button  1010  may be included. The user may type in one or more keywords or other parameters into the search box  1008  and select the search button  1010  to search for content feeds matching the entered keywords and/or parameters. 
     FIG. 11  is a diagram illustrating a data structure for feed content items, in accordance with some embodiments. As described above, a server computer  600  ( FIG. 6 ) may store a plurality of feed content items  620 . The feed content items may be stored in a data structure, such as a table data structure  960 . The feed content items  620  include tagged content items  622  (content items that are each associated with one or more tags) as well as content items not associated with any tag. The feed content table  960  includes a row  970  for each content item from each feed source. Each row includes one or more fields ( 971 ,  972 ) that identify the content item, such as a content ID  971  and a feed ID  972  (which identifies the feed source of the content item). In some embodiments, the content ID may include information that uniquely identifies the feed source, in which case the feed ID  972  may be omitted. Each row  970  may further include content  973  of the content item. The content  973  may include the metadata of the content item (e.g., title, description, URL, date/time, and possibly other metadata), and may further include the actual content of the content item. In addition, each row  970  includes a column  975  or field for each registered user of the system. The user data in this column may include a viewed flag  976 , which indicates whether the user corresponding to this column has viewed the content item associated with the row  970  containing the user data and may optionally include additional user information, such as one or more user specified labels or flags  978 . A user may tag or label content items, as well as content feeds, and a record of the tag or label that the user associated with each labeled content item is stored in the user data  975 . In some embodiments, the system may allow users to tag or label individual content items with predefined tags or labels (e.g., star, red, blue, etc.), and some embodiments further allow users to tag or label individual content items with user-defined labels. Furthermore, a content item, represented by a row  970 , may by tagged by any number of users. 
   As described above, a user may set privacy options to control disclosure (and availability for subscription) of her tagged content items and content feeds to other users at large. In some embodiments, a content aggregation service may be integrated with user address books or contact lists. As a part of the integration, finer privacy options may be made available to the user. The user may use the finer privacy options to control disclosure of tagged content items or feeds to not only other users at large, but also to specific contacts or groups of contacts that are in the user&#39;s address book or contact list. This provides for a wider spectrum of disclosure, ranging to full disclosure, limited disclosure to approved contacts, or to no users. In some other embodiments, the content aggregation service may be further integrated with a social networking service that includes profiles of users&#39; interests and affiliations, among other things. The privacy controls may be further adapted to control disclosure of tagged content items or feeds to other users that may share common interests, affiliations, or the like. 
   The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.