Find message boards that relate to your product and become a guru in your field.
By no means should you use message boards as an aggressive way to promote your site. In the old days (about 2 years ago) webmasters could post whatever they want on message boards, including URL's and other advertisement. Now, this is generally seen as spam and in poor taste. You can use message boards, however, as an effective comminication tools with potential visitors.
Message boards are a good way to interact with other webmasters and customers that are interested in your field of products. You can get your foot in the door, by giving advice and guidance to people on the message boards. This can lead to them asking you about a website or paticular product you are selling. Try to become a guru in your product field and visitors will field more comfortable when they are visiting your site. They will rememebr that you know what you are talking about, and that your endorsement of a product is to be trusted.
I would call message boards a good way to passively promote your site. Visit them when you feel like doing something different for a change, and get involved in discussions with possible customers. Becoming an "expert" in your product line will increase your sales and enhance your websites credibility.
