By submitting to a search directory, you get a back link to your web site. When your site is listed in search directories, this increases the chances that search engines will index it sooner, compared to when it is not listed. Submitting to search directories is a good Web marketing initiative. Because that increases the chances of having your web site index and when your site is listed in a search directory, you list its URL as well, so you actually get a valuable link

Submitting to search directories neither gets higher ranking nor gets your web site certified.