Forums are not only good ways to expose your blog but you can actually earn from these sites. Few forum sites that pay you per post:
Write and get paid $.10 a post. For those that are putting a lot of time and are working full time for the site, they will be paid $.15 a post. Payment is by paypal.
You get paid per post. But the site has not provided for the exact pay per post.
Post in forums and earn points. Points are then converted into cash. Has a referral system where you get 25% of your referral's earnings.
As a forum writer you will be on the front lines of a forum population project. Your objectives are to post replies and new topics with a pre-determined amount. You will be working as a team with other forum writers. I was not able to find their mode of payment.