The blogosphere may have a greater relevance on the internet in part because of all the back scratching that goes on among bloggers. Some of the exchanging of incoming links is a very organic. Just people talking about people.
I have probably given Perez Hilton a half dozen over the last few months and I don’t even like him. He probably will never link to me, unless I have an affair with Doogie Howser. I saw him on a trailer for Harold and Kumar go to White Castle and I have decided that he is not gay, it’s all just a publicity stunt.
Some linking that has relevant content is actually very organized. There are Blogging Carnivals. A host blog is linked to from a banner that particpants embed on their blogs. The participants make a blog post that is relevant to a chosen theme and the host links to everyone’s blog posts. This does in fact generate traffic. It improves Alexa rank.