While corporate managers deeply recognize the necessity of e-Business transformation, they face numerous questions and difficulties related to decision-making in the actual formulation of e-Business strategies, implementation methods, and execution processes. This study aimed to derive a research model based on existing studies and literature regarding the interrelationships among various factors associated with e-Business transformation—namely supply chain management (SCM), information technology, customer service, and firm performance—which are pressing issues for managers seeking to pursue e-Business transformation, and to derive managerial implications through empirical analysis of firms across various domestic industries. The empirical analysis results revealed the following: First, the impact of supply chain management-related activities on price was found to be currently weak; however, they were found to influence quality and product variety among customer service dimensions. Second, among supply chain-related activity factors, trading partners' e-Business level, strategic fit, and external environmental awareness were found to influence order information-related activities within customer service. Third, regarding the impact of customer service improvement resulting from supply chain management activities on firm performance, quality and variety rather than price-related factors among customer service dimensions were found to have a greater impact on firm performance. Fourth, the internal e-Business-related technology level possessed by the firm was found to play a moderating role in the effect of supply chain management-related activities on customer service improvement.