1. A method executed on one or more hardware computing devices for recommending audio files to a member of a social network, the method comprising: receiving, at the one or more hardware computing devices, a representation of a first set of audio files associated with the member; receiving a representation of a set of social networking contacts associated with the member; receiving a representation of one or more second sets of audio files, wherein each second set of audio files is associated with at least one social networking contact in the set of social networking contacts associated with the member; determining, using the one or more hardware computing devices, a first set of characteristics based on the representation of the first set of audio files; determining, using the one or more hardware computing devices, a second set of characteristics based on the representation of the one or more second sets of audio files; generating, using the one or more hardware computing devices, a recommendation for at least one new audio file based on the first set of characteristics and the second set of characteristics, wherein the at least one new audio file is not in the first set of audio files; and providing an indication of the recommendation for the at least one new audio file, wherein the set of social networking contacts associated with the member comprises one or more predefined collections of social networking contacts associated with the member in a social networking service, and wherein the set of social networking contacts associated with the member comprises users of the social networking service having at least one personal characteristic common to that of the member, the at least one personal characteristic corresponding to user registration information within the social networking service.
6. The method of claim 1 , further comprising: adding the at least one new audio file to the first set of audio files.