The competition among the products is common in the business environment. However, the impact of a product's competitors in consumers' electronic word-of-mouth (eWOM) communications has received little attention. Drawing from the theory of distinctive processing, this research examines how eWOM affects a product's success in the competitive mobile game market. Based on a dataset obtained from searchman.com, we find that eWOM volume and valence promote games' sales in general. More importantly, we find the moderating effect of the competitors' eWOM. Our findings suggest that review volume of competitors enhances the relationship between users' review volume and games' sales. Moreover, the review valence of competitors decreases the effects of consumers' review volume and valence on games' sales. This study contributes to the academics by providing a better understanding of the influence of eWOM on games' success. This paper also suggests practical implications for mobile game markets and review platforms.