A system and method includes operations and steps for inferring a demographic of a user based on a selection of an advertisement by the user. A media device stream is received from a media device by data processing hardware. The data processing hardware may identify frames of the media device stream for insertion of an overlay. The overlay can include first and second interactive portions corresponding to respective first and second advertisements. The user can select one of the first interactive portion and the second interactive portion corresponding to one of the first advertisement and the second advertisement. The selection can be received by the data processing hardware, and the demographic of the user can be inferred based on the selection.