Many webmasters recommend submitting url of sites to blog directories as this is supposed to help a blog or a website become more visible to the search engines. Submitting blog URL to directories may also help increase the number of site visitor and one way back links that a site receives. The latter in particular applies to directories that do not require a reciprocal link from a site.
The wordpress codex even attests the usefulness of blog directories and encourages wordpress users to add their sites to directory listings for traffic and search engine optimization purposes. There are tons of websites with high PR in the world wide web but many SEO specialists agree that dmoz.org is the best and the most important blog directory.
Of course directories are not only for blogs, they are for other industries as well. For bloggers and web masters, however, taking advantage of blog directories may be a good way to increase search engine visibility and improve traffic.