Sometimes a brand needs to consider how they measure the quality of their online mentions - quantitative analysis of a campaign just isn't enough. It's something that was debated at length at the London MeasurementCamp working group this morning. As there's no such thing as AEV for mentions on Twitter, one way you can do it is to use Twitter Grader. At this morning's session we talked about how to segment tiers of online coverage of a story, and how, on Twitter, Twitter Grader can be used to do this.
For example, your story is picked up by 50 people on Twitter, 20 of which are tier one (top notch), the rest tier two (little reach or influence). So as a measure, you'd look to improve how many tier one Twitter mentions you get for the next story. To give yourself a target that can be measured. It's applying traditional segmentation to the Twitterspere.
Here is an up to date top 10 for the PR industry on Twitter, which I've compiled using Twitter Grader. I'll leave a top 100 to someone else. Watch our for Peter Hay at PR Week who may be working on something bigger also. Rank in brackets is the person's old position.