This is an excerpt from my eBook Social Bookmarking Money...

Social bookmarking is one of the first places the major search engines look for new sites and web pages. Google especially loves new relevant content and will typically give it a temporary boost in rankings. This is known as "Query Deserves Freshness" or QDF. Basically, having links to your site on bookmarking sites helps your new content get indexed quickly and will help it get a temporary boost in ranking. ...