For a couple of years Web directories played a crucial role in the field of search engine optimization for building high quality back-links or even to gain some direct traffic.
A web directory is defined as a Web site containing list of other Websites assorted under different categories and subcategories. Web directories were intended to send traffic/visitors to the websites at the very beginning but later on they were mostly used to build back-links rather than sending direct traffic.
The first thing about directory Web sites is that Google treats them the same as any other web site. So if you submit your Web site to a high page rank good quality web directory then the back-link is going to be helpful for your website other way around a low page rank poor quality directory might not be useful or even might damage your Web site ranking on Google and other important Search Engines.
A web directory might come in different types according to their categories, their listing plan and the way they are maintained. Most of the general and some of the niche directories provide all the 3 below listing options.
Base on their categories type
1- All-inclusive directories: General directories that have all sort of typical categories.
2- Specific directories: niche directories that have just technical categories related to their niche area.
Base on the way they are maintained
1- Human-edited directories: Have a strict and hard-line submission policy and the submitted Web sites are reviewed by the human editors before being included. For this reason the Human-Edited Web directories are of a higher quality.
2- Non human edited directories: Have a less strict submission policy and don’t have a human editorial revision and have less control over their listings.
Base on their listing plan
1- Free listing: Is free of charge, inclusion is not guaranteed and it might take long time for being included (even up to 6 months or one year)
2- Featured link or paid listing: require money for being included. Most of the time inclusion is guaranteed and support fast inclusion (24 or less and up to a week) your link would be placed on top of the free listings and often in a highlighted eye-catching way.
3- Reciprocal link: they require you to link back to their website in order to be included.