Thanks for the reply oninuva
I already post a lot in the forum, I have around 1300 posts. There are a few guys who post a lot also, but I just want to find ways of encouraging more activity from a wider group, because I believe that it is quite close to reaching a point where it would be self-generating - ie, word of mouth etc. It just needs that extra shove to get it to that point. So, I will definately be looking into methods such as you have suggested.