mattp-
I've spent almost 10 years on web forums.Like clockwork everycouple of years on a forum people bitch about it declining, and the spray or whatever driving people away. Sometimes they change something (heavier moderation, memberships, etc), sometimes they don't. Sometimes the members respond to these tactics, sometimes they don't. The best predictor of 'content', in my experience, is user activity. The more people who use the forum, the more content there is. I'm not saying you can't garden to modify the ratio slightly; but it's only slight.
Exactly. This is just how it is.