Also, you can see a sort of meta discussion here on the /r/dataisbeautiful subreddit: http://www.reddit.com/r/dataisbeautiful/comments/1jqz3f/redd... It's kind of hilarious because people leave threads of comments to create new branches.
What I find most interesting is that you can quickly get an idea of how much conversation is in one of these discussions by the number of nodes that are colored (signifying users who have posted more than once).
A very nice feature to have would be to run topic modeling (say, your run-of-the-mill LDA) on the comments, and then colormap the nodes as to preserve the distances in the comment topic vector. This way you'd be able to see threadjacking, etc.
Comments would swing up and down by double and triple digits as early burying/back-patting is overcome by more moderate opinions as the post rises in exposure. Likewise, having a post linked on other large forums would result in new waves of like-minded moderation.
No, I haven't frequented Reddit for a few years now. I expect /r/politics would have been a goldmine for this last fall. I felt it was most apparent on topics that can be construed to involve race.
