The blogs, the websites that offer support for people thoughts, have increased significantly increased. There can now be found on the internet millions of blogs covering almost all the possible niches that one can think about. There are fashion blogs, radio and television blogs, science blogs, travel blogs, blogs that are concerned with giving the proper care to animals, politics blogs and so on.

Because of the great number and variety of these blogs, both the experts in IT and the owners of the blogs have felt the need to group the blogs according to their subject of discussions, making them more easily to reach by the persons interested in the topic they were dealing with. This need was soon fulfilled by the appearance on the internet of the blog directories.

The blog directory is a website which provides a list of blogs which have submitted to that site. There are mainly used in advertising the blog, by posting a link or an address where people can read articles about the topic they are interested in.

Three types of blog directories can be individuated over the internet. The directories that belong to the first group are the ones that charge a fee for every blog that is submitted. The fee can vary from a blog directory to another. The second type is that which has a mixed policy, offering both free promotion of certain blogs, but also charging money for other blogs or types of blogs. There are also directories where the blog submission is free, so that no extra money would be spent on promotion.

As it can be seen, there are useful both for the blog owners who can better promote their site, but also for the blog readers who can find more easily the blogs which tackle the subjects they are interested in.