25. The non-transitory computer readable storage medium of claim 16 , wherein the profile information comprises at least one of: data posted by one or more of the users, data provided by one or more of the users as part of a registration process, or data collected from other sources.
16. A non-transitory computer readable storage medium storing an executable program for sending a message in a social network, where the program performs steps of: receiving from a source of the message or from a user a keyword relating to a subject of the message; retrieving from an ontology source a normalized set of concepts associated with the keyword, wherein the ontology source comprises at least one community-generated ontology source; collecting information from the social network, the information comprising one or more interactions between users of the social network and profile information for the users; identifying a subset of the information that corresponds to the normalized set of concepts, wherein the subset of the information is used to form a global topic model comprising at least one topic; sending the message to at least one of the users of the social network who is associated with the at least one topic; and dynamically updating the global topic model as new information is collected from the social network.