Yeah, I think the best way to do things is to have a bunch of small communities where everyone knows each-other; it would eliminate a lot of conflict and allow for more choices if one of them goes sour — yeah, smaller communities have their drama, but it's rooted in familiarity rather than ignorance, which is the dominant cause in larger communities.

Even when there's drama: small communities tend to heal over time, while large communities just polarize around an "us vs. them" mentality. Human nature makes it impossible for large communities to remain united, since we can only have 150 relationships on average.

That's 150 online and in real life — so the ideal size of an online community would be lower.