Link Popularity Tool:

Link popularity is the total number of web sites that link to your site. Because good link popularity can dramatically increase traffic to your web site. Well placed links are an excellent source of consistent and targeted traffic. And due to recent developments, they can even generate additional search engine traffic to your site.

Most of the major search engines now factor Link Popularity into their relevancy algorithms. As a result, increasing the number of quality, relevant sites which link to your site can actually improve your search engine rankings. There is still no one "secret trick" to getting good rankings, but boosting your site's popularity may give it the edge it needs.