The most important stream of game developers' revenue is arguably via gamer's in-game purchases. Previous literature has identified a number of strong determinants of online purchase intention including values, consumer experience, lifestyle, security, perceived risk, information, and subjective norms and behavioural control. The present study examined the relationship between online mobile gaming addiction and loyalty towards purchase intention of online mobile game in-game apps. The present study comprised 430 students from two major Indian universities who completed a short 28-item survey focusing on three variables (i.e., addiction, loyalty towards online games, and purchase intention towards online mobile in-game features). The results demonstrated that (i) online mobile game addiction shared a significant positive relationship with online mobile game loyalty; (ii) online mobile game addiction had a positive relationship with the purchase of online mobile in-game apps, and (iii) online mobile game loyalty increased game users' intention to purchase online mobile in-game apps. The present study is the first to investigate loyalty and gaming addiction in relation to the purchase of in-game apps. Game developers will always want to facilitate loyalty among its clientele. However, if the engagement strategies used by gaming operators facilitate addiction as a way of increasing purchase intention of online mobile game in-game apps, this raises serious ethical questions which the gaming industry need to address as part of its corporate social responsibility strategy.