The diversification and coexistence of insurance marketing channels have always been the focus of attention in the literature. The previous studies mainly verified the product quality differentiation among different channels from the perspectives of insurance companies and customers (known as product quality hypothesis). Unlike past works, the insurance agent’s perspective was adopted in this study to verify the product quality hypothesis. Results showed that the optimum service performance on the service efficiency comes from the insurance broker or agent, and the direct underwrite channel and life insurance channel can usually obtain the best internal support and assistance. Moreover, agents of insurance brokers or agents of life insurance tend to invest more time to assist the customers during the negotiation and ensure the high quality of the insurance policy change and renewal. To sum up, the product quality hypothesis can only obtain part of the support, indicating that the multiple marketing channels of the non-life insurance industry are oriented to different kinds of service quality, each having their distinct advantages.