I've seen it with another forum, that was small when i joined up, and then the owner pushed it hard and made it the biggest forum of its kind, and gets big advertising revenue.
It was small and friendly and helpful to start with, then more members came, and the mods were struggling to keep up, then the mods had a massive row and half them quit. I think he must pay professional mods now, because its so well moderated, its become boring, every deviation from the toppic is clamped down on.
It still gets massive views and posts, but it just is not interesting to read any more.
I got into a massive slanging match with another member, while all the mods were asleep, so it was all there for everyone to see for a while. he got banned, and I got a ticking off, so never posted there again. Fond memories, wish I'd saved the posts for posterity.