Just don't. For one, you aren't really that popular. I mean, people may know you, but you aren't widely known. I doubt people would join.
Second, if you're starting because of all the talk about Hobo's Army, it just won't work. You have to start something fresh...not someone's idea, even though that Army idea isn't even new itself.
Back on the phpBB2 days we had a few groups...like Anti-....amaniacs, ....amaniacs, gaming systems, and uh...that's the big ones at least.