[metaxis78]

I think it's very community-to-community. They have hot and influential areas, where the network effect is strong enough to overcome the critical mass required. Also, I imagine they have "bad" mods who kill communities, and "good" mods who don't.

[poulsbohemian]

Yeah, that's kind of my assumption as well. And same goes for the various FB groups -- locally, there's one group people go to be deliberately obnoxious and snotty, and the other to be polite and informative, and everybody in town knows which is which.