Social Bookmarking sites are Search Engine Friendly and your links show up in major search engines in less than 1 week. Let people discover your site easily through social sites. Gain incoming links which for search engines is an indication of the popularity or importance of that website.
Social bookmarking is a way for Internet users to store, organize, share and search bookmarks of web pages. In a social bookmarking system, users save links to web pages that they want to remember and/or share. These bookmarks are usually public, but depending on the service's features, may be saved privately, shared only with specific people or groups, shared only inside certain networks, or another combination of public and private. The allowed people can usually view these bookmarks chronologically, by category or tags, via a search engine, or even randomly.
This system has several advantages over traditional automated resource location and classification software, such as search engine spiders. All tag-based classification of Internet resources (such as web sites) is done by human beings, who understand the content of the resource, as opposed to software which algorithmically attempts to determine the meaning of a resource. This provides for semantically classified tags, which are hard to find with contemporary search engines. Additionally, as people bookmark resources that they find useful, resources that are of more use are bookmarked by more users. Thus, such a system will "rank" a resource based on its perceived utility. This is arguably a more useful metric for end users than other systems which rank resources based on the number of external links pointing to it.
It is a convenient and hassle free way of making sure that your site is noticed and marketed in the right group of people. Submitting your site with social bookmarking sites like Digg or del.icio.us will ensure a greater volume of traffic. It is good advertising for your site and best action to take for getting more effective and quality visitors to your web site