There are many ways to generate targeted traffic for your site without spending single penny.
1) Use of social media .It is best tool .Now a days use of social media has increased immensely ,so bookmarking here can pull lot of traffic for us.
2) Listing of our site on various directory sits will also help in increase in references to our site.
3)use of forum sits and mentioning our site over there is another effective way to promote our site.