People often estimate the power of message forums, and as a webmaster, you can benefit from them in two different ways:
1) Posting to forums in your niche
2) Creating a forum for your site
One of the keys to having a successful site is to become the "expert" in your field or topic. You gain credibility by offering advice and finding solutions to problems people may have.
The great thing about posting on message forums is that most of them allow you to add a signature file to your profile so every time you post, a link to your website appears.
Find a forum in your site's niche and become a regular member. Visit frequently with sound advice and helpful hints. Over time you build credibility and people are more likely to visit your website, take your advice and buy products you recommend.
Another bonus about posting on message boards is that many of them are spidered by the search engines. The more posts you have on a forum, the more places your link will appear. That's another reason why it's so important to have a signature on every post.
The best way to find forums in your niche is to simply use a search engine and type your keywords followed by "forums" or "message boards." So if your site is about acne and you're looking for forums on this topic, just type in "acne forums" or "acne message boards".
Having an active forum on a website provides so many benefits to a webmaster:
1) Another venue to post ads
2) Build credibility by posting helpful information
3) Creates more traffic because people will return to read and respond to posts
4) Many forums allow you to email your forum members (more promotion opportunities)
A Bit of Advice...
DO NOT open a forum on your site until you're getting good amounts of traffic. Often times people start one without enough visitors, and it just sits there collecting dust. An empty forum makes your site look uninhabited and unpopular.
Lesson #12 : Traffic Optimization - Use A Tell-A-Friend Script