1. A system comprising: a controller operatively connected within a feedback loop in which the controller: sends parameter values to playback units to cause the playback units to play back video assets in a manner dictated by the parameter values; receives usage information that reflects user actions performed in relation to playback of the video assets while the video assets are presented in the manner dictated by the parameter values; and based, at least in part, on the usage information, adjusts the parameter values that the controller sends to playback units.