The users of microblogging services, such as Twitter, use the count of followers
of an account as a measure of its reputation or influence. For those unwilling or unable to
attract followers naturally, a growing industry of “Twitter follower markets” provides followers
for sale. Some markets use fake accounts to boost the follower count of their customers,
while others rely on a pyramid scheme to turn non-paying customers into followers for each
other, and into followers for paying customers. In this paper, we present a detailed study of Twitter Followers Markets, and we show that it is possible to detect users that purchased followers on Twitter.