In accordance with some implementations, a method for measuring viewership of media content is disclosed. The method is performed on a client system. The client system captures presence data of one or more users of the client system with the camera. The client system then analyzes the captured presence data to determine if a respective user is a participant in a media viewership study. In accordance with a determination that the user is a participant in the media viewership measurement study, the client system determines the media content being presented. The client system creates viewership data based on the user and the media content being displayed in the proximity of the user and transmits viewership data to a server system.