BlogExplosion
Okay so it seems a bit spammy, but it could also be a really interesting way to promote a website.
BlogExplosion is a directory of blogs. What makes it unique is that once you've added your blog to it, you can earn credits by using it to view the blogs of other members of BlogExplosion.
The credits you get can be spent on ads for your blog, or used to direct the traffic of other BlogExplosion users who are surfing for blogs, to your site.
As long as people are actually using it to find real content and read it, and not just clicking buttons to get credits, it could work out okay... I've found a bunch of interesting stuff today using it. The randomness of the blog surfing reminds me a lot of my own Long Tail site.