I used to do the following to gain traffic:
* Write articles on your topic (your site's topic) and submit to article submission sites
* Join to Social Bookmarking Sites and submit your site
* Write a Press Release about your product/services and submit to Free PR Submission sites
* Register and join forums with the same topic/niche
But that doesn't stop there, you should work it out. After 4 to 6 weeks, you would notice that you'll get higher traffic and at the same time you'll gain link popularity.