Since your bookmarks are categorized into different TAGS, you will get very targeted traffic from people searching within a particular TAG. They will click on your bookmark link and visit your site.
Most of these Social Bookmarking sites have high PR, ranging from 5PR to even 8PR! Therefore, search engine spiders visit these sites so often that your links will be crawled almost immediately!
Getting quality one-way incoming links is the main factor to higher search engine ranking. With Social Bookmarking, you can get unlimited 'keyword' links to your site. Having more keyword links that are relevant to your site will result in higher ranking.
Having high PR Social Bookmarking sites linked to your site will improve your site's PR. With a higher PR, you can link to your new/existing sites and improve their ranking too! You can even monetize on it by selling links from your site!
