Links to your site is the most important factor to improve the SEO rank of your site.
One system that helps with this is My Buzz Group. My Buzz Group is the brainchild of Amy Hutton. Essentially, it’s like a bookmarking club. Every time you log in you are given a link and you are required to bookmark this link in socialmarker.com. The link is the website of one of the other members. So, when someone else logs in your link will also be displayed in rotation.
The result is you build your pagerank over time in a very SEO friendly way. Here is a link to more online business tips.