This study aims to identify the key factors for obtaining competitive advantage in the convenience store industry in Taiwan. The investigation is carried out in two phases. In the first phase, we characterize the distinct features of the convenience store industry, by comparing it with some other industries through exploring the financial statements of the leading company in each industry. Exploration results indicate that the convenience store industry has three essential features: positive cash flow (or low operating capital requirement), robust to economic recession, and oligopoly. In the second phase, we aim to identify key successful factors in the convenience store industry by comparing the first two leading companies (7-11 and Family Mart), through exploring their financial statements. Exploration results indicate that economical scale (number of stores operated by a company) is the key successful factor, which brings up two essential competitive advantages: purchasing price discount and brand effect. That is, the larger is the operating scale, the higher is the aggregate sales amounts, and the higher is the purchasing price discount—which as a result leads to higher gross margin. Moreover, the higher is the number of stores, the higher-valued is the brand, and the higher is customers’ preference in choosing convenience stores—which ultimately leads to higher sales amounts per convenience store.