Internet-based shopping business spread rapidly in Korea. Companies are trying to develop and use various strategic competences. The strategies employed by those companies include activities related to the design of shopping site, market positioning, assistance of purchasing process, payment mechanism, and provision of various consumer services. However, the success of these strategies depends on various environmental factors and internal capability of the companies. In this study, I examined four successful Internet shopping mall companies and compared them to draw useful guidelines for Internet-based intermediary business. These four companies were selected because they are all considered successful by now, but brought different background. We found follows. First, each company tried to economize their own historical and developmental background. All of the selected companies were alike in their focus on the whole Internet user group. Customer needs analysis was performed more systematically. The Importance of customer information and the use of it are not sufficient. Second, Each companies consistently emphasized the importance of market-related activities. Despite the differences in initial states, all companies used similar strategies and had similar focus in target market and products. Conclusively, implications from this research for Internet shopping business can be summarized as follows. First, One of the important future directions for Internet shopping mall business is to broaden target market. Second, the provisions of carefully designed customized services are one success factor. Third, As customer traffic increased, the provision of differential customer service becomes a key success factor.