Link building and directory listings are two essential tools when it comes to organic search engine marketing. Having creditable, outside web sites link to your site increases your online popularity in the eyes of the search engines and in turn makes improves your web site’s organic ranking. Backlinks can sometimes be the deciding factor on whether or not your web site is ranked above other similar sites on the SERPs.

There are several was to improve your link popularity:

• Directories
• Blogs
• Link to your site from articles that you write
• Link to your site from a complimentary web site
• Social sites

Often times search directories offer free listings; however, there are some that do require a fee (one-time or monthly/yearly) or a reciprocal link in exchange for listing your web site. Some great free directories to consider submitting your web site to include:

• DMOZ
• Google Local
• Yahoo Local
• Yahoo Yellow Pages
• Yellow Book
• Yellow Pages

This article from SitePro News backs up these points and reiterates the importance of having backlinks and their impact on your web site’s organic success.