No Silk Road for Online Gamers!: Using Social Network Analysis to Unveil Black Markets in Online Games

Online game involves a very large number of users who are interconnected and interact with each other via the Internet. We studied the characteristics of exchanging virtual goods with real money through processes called “real money trading (RMT)”. Œis exchange might inƒuence online game user behaviors and cause damage to the reputation of game companies. We examined ingame transactions to reveal RMT by constructing a social graph of virtual goods exchanges in an online game and identifying network communities of users. We analyzed approximately 6,000,000 transactions in a popular online game and inferred RMT transactions by comparing the RMT transactions crawled from an out-game market. Our €ndings are summarized as follows: (1) the size of the RMT market could be approximately estimated; (2) professional RMT providers typically form a speci€c network structure (either star-shape or chain) in the trading network, which can be used as a clue for tracing RMT transactions; and (3) the observed RMT market has evolved over time into a monopolized market with a small number of large-sized virtual goods providers.