Data map of the RPG Community

[ThirdWizard]

Not sure if reddit.com is a thing you could add, but there are a bunch of RPG communities over there, the biggest being http://www.reddit.com/r/DnD, http://www.reddit.com/r/DungeonsAndDragons, http://www.reddit.com/r/RPG, and http://www.reddit.com/r/worldbuilding I think.