19. The computer program product of claim 16 , wherein the computer readable program when executed on the computer further causes the computer to determine user interests, and wherein identifying the set of users that share the common set of characteristics comprises identifying the set of users that share common user interests.
20. The computer program product of claim 19 , wherein the user interests are determined based on information in a user profile associated with the first user or are inferred from activities associated with the first user.