Anyone who's ever started a forum know's it's not an easy option, it takes a lot of hard work.
When I started my guitar niche forum in 2009 I thought I'd give it a year to get established... it was a slow start, but now, almost exactly a year later it's feeling like it's finally self-sustaining. I still post lot, but don't feel like if I leave it alone it'll die, like not feeding a Tamagochi !
So, if you've started a forum, persevere and eventualy you'll get there.
But don't think it's gonna be easy!