http://www.blogexplosion.com/index.php?ref=RockyMooreFirst, if you do not know what a blog is, you can visit this site and browse the different directories and see very quickly what they are and how useful they can be.
Blog Explosion is a site that is a basically a directory of different blogs around the net. The primary focus of the site is blogs, or sites useful to the blog community.
If you already have a blog and need more traffic, you can list your site for free and receive some traffic. You will get even more traffic if you browse other blogs listed on the site, as you will receive credits when you visit other sites and those credits can be spent to have visitors come to your site. It is usually an exchange you earn one credit for every two blogs you visit. At this time it is usually one credit equals one visitor to your site. This can work out very well.
You can also spend credits on banner impressions that run at the top of the page while browsing sites. This rate varies from time-to-time. Today it is at 1 credit for 17 banner impressions (views of your banner).
Yet another method to earn credits and drive traffic to your blog is through referrals. You can refer other people to Blog Explosion and receive some of the credits they generate. This can help drive a bit more traffic to you.
All in all, it appears to be a good and effective system to promote your site for free.
If you wish to pay to promote your site, they also offer inexpensive advertising methods to send people to your blog. At the time of this post, it only costs $5 to send 500 people to your blog.