When you are looking for ways to optimize your website so that it gets the most exposure possible, often times webmasters overlook internet or web directory submissions.
This can be a major oversight. Web directories are usually human edited and can therefore gain rank of their own. The link to your website once it is submitted is reviewed and then placed where it is believed to be of most benefit to those looking at the directory.
Search engines also use human edited web directories in their page ranking criteria.
This is why submitting your site to a web directory can help you when you are optimizing your website in order to gain more viable traffic for your site.