Um, anyone notice Allen Says (the owner of Warrior forum) as one of the best, if not THE best forum marketers out there?
He's using other people to grow content, awesome content that is and then making money out of it. Pretty smart.
Forum marketing has been a good success for me on niche forums. I do outsource the job, but when you've 50 helpful posts on a weight loss forum, trust me people will look at your posts and buy stuff from you. So that way it makes money.
Build businesses, not quick money makers.