Forums are great for generating a lot of traffic for you site since there a lot of people using them
. Such sites usually work as online communities where people sit around and talk about certain topics. If you want to share your website to them so that they can purchase your products or if you just want to share some information then you can post a link to those sites. Most sites usually allow users to post links and banners on their site so you just need to put in a link for the members.