Method of analyzing data from an online social network having a set of network users. The method includes obtaining topic-specific messages sent by the network users. The messages have social content provided by the networks users, wherein the messages include a marker of interest in the social content. The marker of interest is associated with a topic of the social network. The method also includes identifying the network users that sent the messages having the marker of interest in the social content as interested users of the topic. The interested users are a subset of the set of network users. The method also includes determining a topic-specific influence (TSI) value of a designated user from the interested users in the subset. The TSI value of the designated user is based on a number of the interested users that are registered to receive the messages from the designated user.