A system comprising: a server configured to provide a social networking service, SNS, and a display apparatus configured to communicate with the server, the display apparatus comprising: a display unit configured to display a content video thereon; a communication unit configured to communicate with the server; and a controller configured to receive from the server a plurality of feedback information of the content video based on feedback information of a plurality of users with respect to the content video, the plurality of the feedback information being collected through the SNS, and configured to provide the plurality of the feedback information while the content video is played, wherein the plurality of the feedback information is configured to respectively correspond to playing timings in an entire playing time of the content video, and the system characterized in that: the server is configured to: determine a degree of distribution of the playing timings corresponding to the plurality of feedback information with respect to the entire playing section (Ta); and extract playing sections (t1 - t2; t3 - t4) determined to have the highest said degree of distribution of the playing timings corresponding to the plurality of feedback information among the entire playing section, generate a preview video based on the extracted sections, and wherein the controller is configured to display the preview video on the display unit. a server configured to provide a social networking service, SNS, and a display apparatus configured to communicate with the server, the display apparatus comprising: a display unit configured to display a content video thereon; a communication unit configured to communicate with the server; and a controller configured to receive from the server a plurality of feedback information of the content video based on feedback information of a plurality of users with respect to the content video, the plurality of the feedback information being collected through the SNS, and configured to provide the plurality of the feedback information while the content video is played, a display unit configured to display a content video thereon; a communication unit configured to communicate with the server; and a controller configured to receive from the server a plurality of feedback information of the content video based on feedback information of a plurality of users with respect to the content video, the plurality of the feedback information being collected through the SNS, and configured to provide the plurality of the feedback information while the content video is played, wherein the plurality of the feedback information is configured to respectively correspond to playing timings in an entire playing time of the content video, and the system characterized in that: the server is configured to: determine a degree of distribution of the playing timings corresponding to the plurality of feedback information with respect to the entire playing section (Ta); and extract playing sections (t1 - t2; t3 - t4) determined to have the highest said degree of distribution of the playing timings corresponding to the plurality of feedback information among the entire playing section, generate a preview video based on the extracted sections, and wherein the controller is configured to display the preview video on the display unit. determine a degree of distribution of the playing timings corresponding to the plurality of feedback information with respect to the entire playing section (Ta); and extract playing sections (t1 - t2; t3 - t4) determined to have the highest said degree of distribution of the playing timings corresponding to the plurality of feedback information among the entire playing section, generate a preview video based on the extracted sections, and wherein the controller is configured to display the preview video on the display unit.