Directories provide listings and information on websites within structured categories, allowing users to search for key terms or browse through the subject hierarchy.
The main difference to search engines is that directories are compiled by humans, so that all websites submitted to them need to provide more information than just a URL. The chances of getting listed on the big directories are becoming harder as the sheer quantity of websites overpowers the editorial capabilities of these search tools.
The most popular web directories are:
Yahoo! became the undisputed 'king of the search directories' on the web and, together with Google, received twice as much traffic as the next largest search tool. As a result, it became one of the most essential sites to get listed on, but also one of the hardest. Launched at the end of 1994, Yahoo! was one of the first search tools and employed a large team of editors in the US and in its regional countries.
After 2001, business sites could only get listed by paying a review fee, with the US site leading the way and other regional Yahoo!'s tending to follow the model. More recently Yahoo! has changed the focus of its search capabilities by acquiring its own search engine capability and relegating the directory listings to a supplementary search option, largely because the growth of the web meant that the directory listings couldn't keep pace and remain economical. Listings can still be submitted to the Yahoo! directory, although the value of these is now less than in previous years.
This is a unique directory model that uses a wide network of volunteer editors. ODP (or DMOZ) was acquired by Netscape soon after its launch in 1998 and the directory is made available on an open license arrangement to provide supplementary listings to many search sites, including Lycos, AltaVista, HotBot and AOL Search.
A listing on this directory can take a long time to achieve, depending on the popularity of a section, the availability of a subject editor and the backlog of submissions. More recently this problem has become worse as the importance of an ODP listing for rankings within Google has increased the volume of submissions to the site, which in turn has put more pressure on the dwindling number of editors.
The other main directories on the web now tend to be specialised subject directories, such as business directories or shopping directories. These can still provide ranking and linking advantages to websites and should be considered as part of a submission strategy or link building programme.