Security vendor Barracuda Networks has shed some light on the shady business of people paying to artificially inflate their follower count on the social networking site Twitter.
The practice usually involves end users purchasing batches of "fake followers" to bolster their number of Twitter fans and appear more popular.
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.
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.
"Dealers can apply obscure techniques to make them hard to detect, [for instance] by randomly following some famous and some average people or posting tweets grabbed from the Twitter stream," explained the firm.
"This is one reason that the prices of followers vary dramatically on eBay and other online websites, ranging from $2 to $55 per 1,000 followers. The higher the price, the more real these followers look."
The vendor also identified more than 72,000 fake Twitter accounts, which were typically set up around five months ago and follow an average of 1,799 users.
"Fake accounts normally follow a lot of people, but normally no [more] than 2001, indicating Twitter may internally use this number as a cut-off for abused account detection," said the company in a blog post.
Meanwhile, 75 per cent of the people who buy fake followers have a URL in their profiles and nearly 49,000 followers.
"[Having a URL in your profile] means they might buy followers for website promotional purposes," suggested the post.
Jason Ding, research scientist at Barracuda, said the company was amazed by the size of the fake follower trading market.
"Creating fake Twitter accounts and buying followers is against Twitter's terms of service and gradually erodes the overall value of the social network," he said.
"If [Twitter] does not move faster, these fake accounts will continue to be created, blending into the massive Twitter population, bringing bigger and bigger impact."
