You must follow Ethical SEO techniques.Blogs,forum submissions,internet directory submissions,external blog commenting,social bookmarking are some effective ways of promoting your website over the Internet. In the meantime you can keep working on building backlinks from niche good quality websites with better PR.
I agree with SEO suggestion. Three things one has to concentrate to gain traffic through search engine optimization. First is relevant and quality content on a particular keyword usually related to the product/services. Second is link building, link exchange and reciprocal linking so more sites will be pointing to your site as reference. Last one is social media participation so people who have an account on these social media sites will get to know your site.