Systems and methods are provided for analyzing people's interests, based on signals available within social media. In general, the systems and methods can include determining interests for a group of people that differentiate the group from another group. First, topics of interest for each individual can be calculated based on topics associated with their activity on social media websites and topics associated with people in their social media network. The interest topics of people in a first group can be compared to the interest topics of people in a second group to determine which interest topics have a high affinity for one group but not the other. The invention can further provide for visualization of the topic distribution between the two groups, which can include illustrations of the number of people in each group who are interested in a plurality of topics and/or the prevalence of each of the plurality of topics in the first group relative to the second group.