A web directory is a directory on the World Wide Web that specializes in linking to other web sites and categorizing those links. Web directories often allow site owners to submit their site for inclusion. Human editors review submissions. Famous web directories are Yahoo! Directory, LookSmart, and the Open Directory Project. ODP is an important player in the directory market, perhaps because of its open content approach to editorial review and its use by Google. Zeal, also open to contributions from volunteers, is the non-commercial side of LookSmart's directory, and its material is reused on various sites. A debate over quality in directories and databases continues, as search engines use ODP's content without real integration, and some experiment using clustering. There have been many attempts to make directory development easier, whether using a "links for all" type link submission site using a script, or any number of available PHP portals and programs. Recently, social software techniques have spawned new efforts of categorization, with Amazon.com adding tagging to their product pages. Human-edited directories are often targeted as part of a strategy for being indexed in the major search engines. The idea being that a new site needs to quickly build inbound links from reputable sources in order to have higher rankings within search engine results.

This is a list of unique directories listing World Wide Web sites (Wikipedia, 2006).

• Answers.com - Provides a portal to more specialized "directories" (including Wikipedia) depending on what category of information you are seeking.
  Best of the Web Directory - Provides a general directory of content rich, well designed websites categorized topically and regionally.

• Gimpsy - A directory organized by activity.

• LinkCentre - Free web directory established in 1996 and built by web publishers from around the world.

• LookSmart - Operates a mainly commercial directory, with some free content from its Zeal community program for non-commercial entries.

• Open Directory Project (aka DMoz) - The largest directory of the web, licensed to mirror sites, such as the Google Directory.

• World Wide Web Virtual Library (VLIB) - The oldest directory of the Web.

• Yahoo! Directory - Their directory was their principal founding service.

• Zeal - Volunteer-built web directory, first appearing in 1999

Directory marketing helps in boosting the business performance of a company. It can provide qualified leads for business and the website will also increase its traffic. Some basic advantages of online directories are: substantial staying power. repetitive marketing, growing listing with the entire site, no need of constant updating, and no need to link back to the directory. Some links to online directories are http://dir.yahoo.com, http://www.dmoz.com and http://directory.google.com. With web marketing, the user seeks to have ever lasting staying power and online directories can provide the user with this and more. Every major city has at least one or two good business directories for the user to submit his business to. Many of these directories don't even require that the user must have a website.