1. A method comprising, by one or more processors associated with one or more computing devices: accessing a social graph comprising a plurality of nodes and a plurality of edges connecting the nodes, each of the edges between two of the nodes representing a single degree of separation between them, the nodes comprising: a plurality of user nodes corresponding to a plurality of users associated with an online social network, respectively; and a plurality of concept nodes corresponding to a plurality of concepts associated with the online social network, respectively; accessing user-concept scores for a first set of user nodes of the plurality of nodes, respectively, each user-concept score being with respect to particular user-concept pairs comprising a user node from the first set of user nodes that is connected by an edge to a concept node from the plurality of concept nodes; generating a recommendation-algorithm for estimating recommended user-concept scores for all user-concept pairs in the first set of user nodes and the plurality of concept nodes, the recommended user-concept scores being based on the accessed user-concept scores; and calculating recommended user-concept scores for a second set of user nodes of the plurality of nodes, the first set of user nodes being discrete from the second set of user nodes.