Originally Posted by Ulrich

Seems you don't have relevant backlinks. In other words people are finding your site, but from the wrong places so the folks who end up landing on your site aren't really interested in what you've got. That doesn't necessarily mean that you're content is poor, but more that you've got the wrong targetted visitor-group.

As mentioned you'll have to target your keywords more carefully in order to attract more targetted-traffic. Link to pages similar to yours and click those links if you have to so that those site owners take note of yours, if your site has good content people with relevant content will start linking to it in due time.

Alternatively you can find sites similar to yours and request a link-exchange, but remember to place the link in a contextual manner and provide useful information to your visitors at the same time.

Good luck!