If you go the forum route, you have to become a contributing member of the forum, not just a spammy advertiser. Forum members are pretty good at smelling out spam. If you have something to contribute to the discussions then go for it and place a sig line (if they allow it), you will get a small amount of traffic, but it’s the extra learning and understanding of player issues that you should find more helpful. Some forums do have spam sections for those that want to just post ads, but you can guess how many people look at those.
Oh, and one last thing to add. Read throught he forum rules before posting anything, some forum owners will be quite vigilent in protecting the integrity of their forum…as they should be.