New York Times has a story about a study called “Measuring User Influence in Twitter: The Million Follower Fallacy” by Meeyoung Cha and Hamed Haddadi and Fabricio Benevenuto and Krishna P. Gummadi.  The NYT article says:

“The conclusion? Those with the largest number of followers may be “popular” Twitterers, but that’s not necessarily related to their influence. . . . The data the researchers had access to is astounding: 54,981,152 user accounts, 1,963,263,821 social (follow) links and 1,755,925,520 tweets. . . . In the end, what the researchers found was that follower count alone is not necessarily a worthy measure of determining influence.”

See the authors’ research paper.