Barracuda Networks recently published the results of a study entitled 'The Underground Economy of Buying Twitter Followers: Dealers, Abusers and Fake Accounts,' which examines the practice of paying "dealers" for fake Twitter followers.

"Barracuda’s research team has been tracking the initiative since May 2012, and discovered the average selling price of a batch of 1,000 followers is $18," writes IT PRO's Caroline Donnelly. "The higher the price, the more real these followers look. As part of its investigation, the firm set up three Twitter accounts and purchased between 20,000 and 70,000 followers for each one from online auction site eBay. Through this, the firm discovered 20 eBay sellers and 58 websites offering fake followers for sale, and claimed some of them could be making up to $800 a day."

"This isn’t the first time that we’ve heard that Twitter is riddled with fake and inactive accounts," writes WebProNews' Josh Wolford. "One analyst recently said that Twitter had crossed the 500 million account mark -- but not active users. A couple of months ago, Twitter CEO Dick Costolo announced 140 million active Twitter users. As you can see, there’s a discrepancy here between active users and total accounts. A big one."

"To put a face on this underground Twitter economy, Barracuda Labs took a hard look at presidential candidate Mitt Romney’s 17 percent spike in new Twitter followers on July 21st," writes AllTwitter's Lauren Dugan. "They found that one quarter of these followers were less than 3 weeks old, and 80 percent were less than 90 days old. And, 10 percent have already been suspended by Twitter -- not a good sign."