My community is a bit too niche for this. That and now forums get a lot of competition from facebook and such.
If you think about it, before blogs, the only place people could express themselves online was forums for the most part.
Then blogs came along and forums probably lost their top 2 or 5% to people with motivation and talent starting their own blogs.
With facebook, so much of the conversation happens there, among friends and family and coworkers, that getting much activity on forums is much harder to do.
I wouldn't start a forum for my topic today, it would be waaaaay too hard to get off the ground.