Well, You have to decide what really are you looking for. Increase site's rank, better SE positioning or increase traffic. Each may be to some degree related... But are different things. For improving you site's Rank you need to create backlinks to other high PR sites (preferably related to your niche). But for traffic you need to advertise on sites that will deliver visits... Social networking, forum, social network and blog commenting, solo ads or email marketing and even traffic exchange... You can also try classifieds and Google AdSense. But Google AdSense can rack up a hefty bill if you don't know what you are doing.
