This research-in-progress paper aims to investigate the determinants for the successful usage of social network services (SNS) from the perspective of a firm. A new type of commercial community operated by a firm in public SNS is defined as a firm’s SNS page and the success of encouraging users’ adoption and continued usage of a firm’s SNS page is further defined as SNS success. Based on solid theoretical foundation of communicative ecology theory, a conceptual research model of SNS success is proposed. It is composed of the content quality, service quality, and social interaction quality as antecedents. Among these elements, social interaction quality is newly developed to reflect the value of interaction among community members as a second-order variable which consists of exchange information, social support, and friendship. In addition, incentives and the network size are examined as moderating variables. After building the research model and hypotheses, the measurement scales and the results of a pilot study to verify the items are described. At the end of the paper, the conclusion and the expected contribution are discussed.