A method for determining a popularity of a user includes identifying an online identity for which a popularity measurement is to be determined, and identifying one or more other online identities based, at least in part, on their being within a specified number of degrees of separation of the online identity. Popularity measurements for the other users are accessed and aggregated, and a popularity measurement for the user is determined based on at least the aggregated popularity measurements for the other online identities. A graphical user interface includes a first identifier specification mechanism that enables specification of an identifier of a first online identity, and a second identifier specification mechanism that enables specification of an identifier of a second online identity. The graphical user interface includes a display of an indication of whether a popularity of the first online identity exceeds a popularity of the second online identity.