Why not advertise your Forum in the Marketing Sub-Forum. Here is a very good example of what Peterssidan did. Maybe you could offer X coins for people to register and Y coins for posts.
I think for any forum to succeed these days it needs to be a niche forum,general forums are so difficult to get off the ground,people need a reason to go to and post on a forum,rather than just a general chat,they can get that on Facebook.
Your URL says trading in it,but I don't see your forum as a trading forum,I just see the same mix of categories you would see on any forum,if I was to make a suggestion it would be to narrow down your scope and try to identify a niche.
Its good, will try to find sum time to log on it