"Search engines rate a site based on relevance of links on a site. A bunch of links pointing to all kinds of topic would fragment your rank in different directions. If you are a fashion designer, link to sites in similar space rather than linking to sites about pizzas or fiscal cliff. Keep your content focused to the core of your business and the relevant links will automatically fall into place.
Make sure that 80% of the links on your site are focused and to the point. Relevant links on your site boosts your rank for the category. Check your pages again and clean up the links that do not align with your business. Once done, you won’t see the result overnight. But you will see the impact in the long run.
Back links are the difficult part. It could take some persuasion to get the right sites to link back to you. Over time, you will accrue some decent back links!"