With keen competition in the online game industry, game developers and publishers are finding new ways to induce players’ to spend money on subscriptions and virtual items. As the online game itself pro- vides a highly engaging environment, this study examines online sales from the perspective of customer engagement. We propose a research model that examines why game players actively engage in playing online games, and how such engagement can contribute to sales of online games, empirically testing the model using 377 online game players. The results support our research hypotheses and illustrate the effect of customer psychological engagement on stimulating game players’ spending in online games. In particular, both psychological and behavioral engagement exerted a positive influence on online sales, and the dimensions and antecedents of psychological engagement were also identified. The findings of this study are expected to provide some suggestions for game developers and publishers on promoting the sales of digital items/goods. This study also adds to the current understanding of customer psycho- logical engagement by identifying its antecedents and consequences in the context of online games.