Abstract: In the e-commerce market, the success of the hybrid online platform is well proven. The platform is not only an e-retailer but also provides online logistics services for other e-retailers in the platform. Logistics service is an indispensable link in e-commerce, and it also plays a vital role in promoting the online shopping. In our research, we analyze the impacts of logistics service sharing between the platform and the e-retailer and investigate the optimal strategy in two models. The study found that when the third-party logistics provider's logistics service level coordinates with logistics service fees and both are in the middle range, the platform and the e-retailer can achieve a logistics service sharing agreement, forming a win-win scenario. When the logistics service fee charged by the third-party logistics provider is too low, or the third-party logistics provider's logistics service is too high, both the platform and the e-retailer will choose the strategic mode of not sharing logistics service. Simultaneously, the third-party logistics provider's logistics service level promotes the logistics service level of the platform. Finally, numerical analysis is carried out to verify the equilibrium model and analyze the impacts of the equilibrium model's main parameters. Our study contributes to the growing body of research on the platform operation and provides management insights on firms' logistic service strategy choices.

Key words: platform, e-commerce, logistics service, coopetition