Top brands, celebrities, shows on Twitter

She doesn't even Tweet, yet she's the top celebrity on the micro-blog site

What do Zappos, Ana Marie Cox, CNN, and Britney Spears have in common? They're the most popular brands, celebrities, media personalities and television shows, as tracked by Tracking Twitter, a real-time listing of top feeds being tracked on Twitter.

The rankings are based on the number of followers.

As you can see from the rankings below, Zappos has more than 179,000 followers while Britney Spears has over 283,000 followers, even though, according to Tracking Twitter, she's not "really" updating.

Note from the graph below, her Tweets are "updated by her staff."

Is this a new measure of popularity? It sure feels like it. Here are the top feeds for brands.

 Here's the top feeds in the media category:

 Here are the top feeds in the television category: