A content hosting system comprising: a front end server operatively connected to a mobile device via a network, configured to receive therefrom a request to watch digital content; and a content server configured to send graphical representations of a plurality of videos corresponding to the digital content for presentation on the mobile device; characterised in that, the content server is further configured: responsive to a user scrolling to a graphical representation, presented on the mobile device, of a first video of the plurality of videos, to determine that the current playback mode is an automated playback mode and automatically begin playback of the first video in the automated playback mode; upon detecting the user pausing video playback, to switch the current playback mode from the automated playback mode to a pause mode characterized by requiring a user instruction before starting video playback wherein the pause mode is to be used for playback of the plurality of videos until detecting a user instruction to start video playback; and responsive to a user scrolling to a graphical representation of a second video of the plurality of videos, to determine that the current playback mode is the pause mode, and refrain from beginning playback of the second video until receiving a user instruction to play the second video; and wherein the content hosting system further comprises a user behaviour server configured to set a profile instruction to use the user's preferred playback mode. a front end server operatively connected to a mobile device via a network, configured to receive therefrom a request to watch digital content; and a content server configured to send graphical representations of a plurality of videos corresponding to the digital content for presentation on the mobile device; characterised in that, the content server is further configured: responsive to a user scrolling to a graphical representation, presented on the mobile device, of a first video of the plurality of videos, to determine that the current playback mode is an automated playback mode and automatically begin playback of the first video in the automated playback mode; upon detecting the user pausing video playback, to switch the current playback mode from the automated playback mode to a pause mode characterized by requiring a user instruction before starting video playback wherein the pause mode is to be used for playback of the plurality of videos until detecting a user instruction to start video playback; and responsive to a user scrolling to a graphical representation of a second video of the plurality of videos, to determine that the current playback mode is the pause mode, and refrain from beginning playback of the second video until receiving a user instruction to play the second video; and responsive to a user scrolling to a graphical representation, presented on the mobile device, of a first video of the plurality of videos, to determine that the current playback mode is an automated playback mode and automatically begin playback of the first video in the automated playback mode; upon detecting the user pausing video playback, to switch the current playback mode from the automated playback mode to a pause mode characterized by requiring a user instruction before starting video playback wherein the pause mode is to be used for playback of the plurality of videos until detecting a user instruction to start video playback; and responsive to a user scrolling to a graphical representation of a second video of the plurality of videos, to determine that the current playback mode is the pause mode, and refrain from beginning playback of the second video until receiving a user instruction to play the second video; and wherein the content hosting system further comprises a user behaviour server configured to set a profile instruction to use the user's preferred playback mode.