Obtaining content quality feedback by placing content in advertisements

Content providers often benefit from feedback on the quality of their content before it ships to a broader audience. Separately, app developers aim to maximize revenue and online users prefer more interesting advertisements. This disclosure uses online advertising slots to display test content produced by content providers. Users that watch the content are asked to rate the content. Alternately, if the viewing user permits, a device camera determines user reactions, e.g., facial expressions that are indicative of pleasure, displeasure, or boredom with the content. Prior to distribution of content to the general public, such content can be shown to a control group such that the content provider or creator can gauge the effectiveness of the content