Online Social Networks act as a popular forum to promote and manage the reputation of aristocrats. Generally, big organizations, politicians, celebrities, and journalists require a huge number of followers/fans to promote and manage their reputation on Online Social Networks such as Twitter. This demand of more followers has originated Twitter Followers Market that deals with the sale and purchase of fake/compromised Twitter accounts. In this paper, an analysis of merchants of this marketing industry has been conducted using graph- and content-based features. The present study has been conducted by collecting 15,750 tweets related to the sale or purchase of Twitter followers posted by around 995 users. The analysis infers that the merchants of this marketing industry fulfill the characteristics of spammers as stated by the rules and policies of Twitter. Further, machine learning classification approach has been used to categorize these merchants from genuine users based on their behavioral features. To the best of our knowledge, this is the novel study to analyze and then categorize the behavior of such merchants involved in the sale of Twitter accounts as spammers.