My response to your post:
http://agitationist.com/1500-m.....comment-17

And conversation is what this is all about. To the extent that a brand wants to know what people are talking about, it makes sense for them to track, in aggregate, the conversations about them on Twitter and other social media. Trying to single out influencers can only buy them time–after all, if they are influencers, their influence will show in the propagation. But that time might be critical, so I could see why a brand would make the extra effort.

I agree that the gaming of the number of followers will be a problem. It has already started in some spots. “Does anybody care” about authority/influence? I am not sure. Though I do like your idea of brands tracking influencers. However, the brands will know the influencers from outside of twitter, like a blog, and hopefully know who they should be following. Thanks for the excellent comment.

A much better thing to measure would be actual influence, but that’s hard to do quantitatively. But the idea is this: how much do someone’s tweets affect the collective conversation? Re-tweets are a step in the right direction, though even those can be gamed.

There’s still a question as to whether anybody cares, other than those few who expect such a measure to help them gain influence personally. But if you’re a company using Twitter to monitor your customer base, it’s probably a good idea to monitor known influencers more carefully, rather than just waiting for the avalanche of influence their tweets will eventually trigger.