1. A system comprising: a processor; a non-transitory computer-readable storage medium coupled to the processor, the computer-readable storage medium having instructions encoded thereon that, when executed by the processor, cause the processor to: receive, at a social networking system, contact information for a plurality of contacts from a first user of the social networking system; store, by the social networking system, the contact information for the plurality of contacts in user profile information associated with the first user; retrieve stored user profile information associated with one or more other users of the social networking system, wherein the one or more other users do not include the first user; receive, at the social networking system, from the first user additional contact information for a particular user of the social networking system, wherein the one or more others users includes the particular user; determine, by a processor, which of the one or more other users of the social networking system are not connected to the first user in the social networking system based on the retrieved user profile information; compare the received additional contact information for the particular user with the retrieved user profile information associated with those of the one or more other users of the social networking system not connected to the first user; responsive to a match between at least a portion of the retrieved user profile information associated with a matching user of the one or more other users not connected to the first user and the received additional contact information for the particular user, select the matching user of the social networking system for recommendation; and recommend to the first user a connection be made between the first user and the matching user in the social networking system.