Every retailer faces competition, either directly or indirectly. This note examines how a retailer can systematically conceptualize and analyze his or her competition in order to make better retail marketing decisions. The two key topic areas are retail formats (a way to classify retail competitors) and competitive analysis. Every retailer needs to find some reason why customers should buy from him or her rather than from a competitor - in short, a competitive advantage. Gaining competitive advantage requires not only customer understanding, but also competitive understanding.