hi guys i have a forum with forumotion free hosting etc etc i have seen similar forums to mine who have been established along time ie 2 years but have less members than i have made in 3 months so far i have 241 members and my statistics are as follows this is just for these 2 months january 09 and feb 09 Summary (Yorkshire-suzuki)
Why don't you use your own hosting? Coz by using free host there are a lot of restriction such as affiliate link not allow. You can earn more by charging member fee in order to get access to the forum. And charge commission when there is a transaction closed in your foum.
Host yourself man.. Get a host, you can get cheap, fairly reliable hosting from all sorts of places on the net.. (look at webhostingtalk or something.. ) This way you can earn money from adverts, (AdSense, YPN, etc..) you can also have a donation button.. possibly integrate that with a "donators" group who have special priviledges on the forum or something.. Forums have many money making options... But most of which is dependant on you having full control of your forum (ie host it yourself) Chuckun
it is interesting if you can see the search terms ppl use to come to your website. Try to investigate who they are to be able to choose the best aff product to promote.