Unfortunately, this is a classic example of what goes wrong when one tries to apply a mass-media/mass-marketing mindset onto a personal medium. Ineviatably, “influence” will be equated with mass and link-popularity. However, in reality, “influence” is not always measured by the quantity of people who link to you. It’s the “who,” not the how-many.
Moreover, bloggers are NOT omni-influential. Jeff Jarvis may influence my perceptions regarding media, but his Dell-ranting is not going to influence me. (It may entertain me, but am I influenced?) If mass-marketers try to “figure out” the blogosphere with some sort of “measurement tool” rather than by joining in the conversation and “belonging” to the blogosphere, they’re missing the point and will remain clueless outsiders.