David Armano, in his Logic+Emotion Blog, writes a great post about a presentation he is creating to educate Digitas employees on the power of blogging. One concept he wants to explain is the fact that a "Sphere of Influence" in the blogosphere exists and he offered up a visual representation.
This is an extension of the A-List/B-list concept, but he feels that using that type of language makes them sound like "micro celebrities". Instead, he takes a more logical approach and breaks down bloggers by their "Levels of Influence," based exclusively on the number of links to them. I like this approach, but if you read the comments, there is a debate going on. There are other factors involved, but in-bound links seem to me to be a great start.
Look at it this way. What has more influence, Blog A that has 1,000 avid readers who don't talk about it with others or Blog B with 100 readers who will all blog about what they read there? I think Blog B has more influence because the influence expands beyond itself to the other blogs. Roper's "The Influentials" calls this the "multiplier effect". Links are a great way to determine this.
(via Jaffe Juice)