Some of the best online communities I've been a part of in the past are ones that no one outside of that niche group knew about. Now obviously, that can be very limiting if the people on that site ONLY talk about that one and only one subject, but making a site too vague and too big can be an issue (ex: Reddit).
I'm there there are greedy mo-fo's watching. All it takes is someone with a nice big lump sum offer to the people that run the servers and that someone with revenue in their minds will sprinkle ads and premium features all throughout the instances.