The study cited researched communities at CNN, IGN, Breitbart, and allkpop. How similar are these communities to Reddit? (A serious question; I've never participated in any of them.)

To be clear: The article bases its analysis of Reddit on the study,[1] which examines the communities named above but does not mention Reddit.

[1] http://cs.stanford.edu/people/jure/pubs/disqus-icwsm14.pdf