At first glance, this looks like another ego list—something many folks who are involved in the social space will tell you to ignore. What I see here isn't really a list—it's simply an updated artifact that illustrates one facet of a current intennet phenomenon called the "retweet", Twitter's version of viral activity.
Why You Should Care About Retweets
If you are a small, medium or large business/brand looking to figure out how to engage in networks—understanding the art of the retweet is something I think you should take seriously. As I look down this list, I see common denominators that are very telling about the intricacies of social media. For example, Guy Kawasaki scours his Alltop headlines looking for high quality links to content. These are seen as a "service" on the network and are rewarded with retweets. In return, Guy's footprint, influence and business model in this space continue to grow. Mashable, a niche Web 2.0 publication follows a similar model and reaps similar rewards. What's worth noticing here is for Mashable!, the Twitter profile becomes less about the individual behind it (Pete Cashmore) and more about the brand he founded. Again, value and service are themes n both.
What People Are Talking About
Retweets also provides an insight not only to what people are talking about (there are a number of ways you can track popular topics in the Twitter network includiung search.twitter.com but tracking retweets around a topic or user will also tell you something about the popularity of that topic (see @inaug above).
Why Brands Should Care About This
Brands need to understand every nook and cranny about how and why things "go viral" in and out of every network. The most common mistake brands make is producing a piece of content an calling it "viral" before it ever actually is worthy of this claim. Most never even get close. Studying the people, organizations and brands that regularly get talked about can help us understand the social nuances of each network and what acts as currency in these. Many markerters are looking for a quick fix as opposed to "going deep" and realy studying how these networks function.
Sociology and marketing are on a collision course.
So make efforts to understand why people do things like "retweeting"—what's in it for them and for the individuals and organizations that have figured out how to tap the viral nature of any network. One of the reasons I'm continuing to look at the retweet is because I've witnessed it's power first hand and have seen how it's NOT contained to one network but connects several. And I'm less concerned about adding a "tweet this" button to everything I do as much as I am to providing a valuable service.