12. The method of claim 10 , wherein increasing the social rank value assigned to the followed node for the type of subject matter when it is determined that any of the one or more following nodes are interested in the type of subject matter comprises: identifying one or more of the interested following nodes which has assigned an importance rating to the followed node as rated nodes; for each rated node, (1) calculating an increase amount as a function of the importance rating assigned by the rated node to the followed node, and the social rank value of the rated node, and (2) increasing the social rank value assigned to the followed node for the type of subject matter by the increase amount.
10. The method of claim 1 , further comprising: identifying a compatibility topic; for each node, obtaining a compatibility rating for the compatibility topic based on an analysis of similarity between social data associated with the particular user and social data associated with the node; determining whether the search criteria is related to the compatibility topic; obtaining a proximity rating for each of the plurality of nodes, the proximity rating indicating at least one of (1) a distance between the node and the particular user on the social graph, or (2) a physical distance between an entity represented by the node and the particular user; identifying a type of subject matter; identifying each of at least a portion of the plurality of nodes as a followed node, each followed node being followed by at least one other of the plurality of nodes in the social graph, a social rank value having been assigned to each followed node for the type of subject matter; for each followed node, identifying one or more of the plurality of nodes that are following the followed node; for each followed node, (1) analyzing social data associated with the one or more of the nodes following the followed node to determine whether any of the one or more following nodes are interested in the type of subject matter; and (2) increasing the social rank value assigned to the followed node for the type of subject matter if it is determined that any of the one or more following nodes are interested in the type of subject matter; and determining whether the search criteria is related to the type of subject matter; wherein for each of the search results in which one of the plurality of items of interest was identified: (i) the node value for each node identified is based at least in part on the proximity rating associated with the node, (ii) if it is determined that the search criteria is related to the compatibility topic, the node value for each node identified is based at least in part on the compatibility rating associated with the node and the compatibility topic, and (iii) if it is determined that the search criteria is related to the type of subject matter, the node value for each node identified is based at least in part on the social rank value assigned to the node for the type of subject matter.