Some examples include determining a proximity between a first user device and a plurality of other user devices based at least in part on comparing location information of the first user device with location information for the plurality of other user devices. Additionally, a commonality may be determined that is associated with at least some user profiles of the other users, but is unassociated with a user profile of the first user. For example, the commonality may have a frequency of occurrence among the user profiles of the other users that is greater than the frequency of occurrence among user profiles associated with a larger population. In other examples, a first portable computing device may receive profile information from a nearby second portable computing device for determining a compatibility between a first user profile and a second user profile.