you promote your sitewith the help of social boobkmarking and networking it really help you to get more traffic.
if you want good traffic then spend some money and take help of PPC. PPC is the best way to generate traffic for your site.. otherwise you go through with social bookmarking networking forum posting, question and answers and much more.
idea: develop a section just on free helpful articles and write away - optimize articles for search engines. do some internet marketing over 30 days . . .
drive organic, free and ever growing traffic
cost: time and brain power
You should have started a blog first to gauge interest in your topic. You could have added lots of useful, relevant content, slowly built up your credibilty and traffic, and then once your blog was successful, gradually transferred your blog readers over to your forum.
Link building is a good source for generating good quality back links as well as traffic. It is generally used for generating the back links. However social networking sites are also good place where you can promote your product and generate heavy traffic.