  In the massive online worlds of social media, users frequently rely on
organizing themselves around specific topics of interest to find and engage
with like-minded people. However, navigating these massive worlds and finding
topics of specific interest often proves difficult because the worlds are
mostly organized haphazardly, leaving users to find relevant interests by word
of mouth or using a basic search feature. Here, we report on a method using the
backbone of a network to create a map of the primary topics of interest in any
social network. To demonstrate the method, we build an interest map for the
social news web site reddit and show how such a map could be used to navigate a
social media world. Moreover, we analyze the network properties of the reddit
social network and find that it has a scale-free, small-world, and modular
community structure, much like other online social networks such as Facebook
and Twitter. We suggest that the integration of interest maps into popular
social media platforms will assist users in organizing themselves into more
specific interest groups, which will help alleviate the overcrowding effect
often observed in large online communities.

Social and Information Networks;Physics and Society