1. A computer-implemented method comprising: receiving, at a computer system, a request to identify interests for users of a social network; accessing, by the computer system, a graph that includes i) nodes that represent at least a portion of the users of the social network and ii) edges that connect the nodes and that represent relationships among the portion of the users of the social network; assigning labels to at least some of the nodes of the graph based, at least in part, on content that is associated with the portion of the users on the social network, wherein the labels correspond to topics of user interest; determining, for the at least some of the nodes, label values for the assigned labels based, at least in part, on content that is associated with users that correspond to the at least some of the nodes, wherein the label values determined for the at least some of the nodes and the assigned labels indicate degrees to which the users represented by the at least some of the nodes are interested in the topics that correspond to the assigned labels, wherein a first label value for a first label and a second level value for a second label are determined for a first node and a second label value for the second label is determined for a second node, the first node and the second node having an indirect connection between each other that comprises a portion of the edges and one or more other nodes; iteratively propagating, for at least a threshold number of iterations, the label values in the graph based on the nodes and the edges of the graph, the iterative propagation causing at least a portion of the second label value for the second node to be propagated from the second node to the first node through the indirect connection between the first and second nodes, wherein propagation of the at least a portion of the second label value for the second node causes the first label value for the first node to decrease or the second label value for the first node to increase, or both; and providing, by the computer system, the determined label values for the nodes that result from the iterative propagation.