1. A method of expanding an audience measurement panel, comprising: determining if a received indication identifying access to media was sent by a member of the audience measurement panel; if the received indication identifying access to the media was not sent by the member of the audience measurement panel, forwarding the indication to a social network provider, wherein forwarding the indication to the social network provider comprises forwarding a modified value of a site identifier indicative of a publisher website of the media; and if the indication was sent by a user of the social network provider, receiving a log associating the access to the media with first demographics of the user stored in records of the social network provider.