Online reviews serve as a crucial nexus between products, e-sellers, consumers, and platforms in e-commerce. These third-party evaluations help mitigate consumers' information asymmetry about product quality significantly affect their purchase decisions. Thus, online reviews also have significant impacts on firms' operational behaviors, usually predicated on product quality and consumer behavior. On the one hand, for e-commerce platforms, selling format decisions are critical. There exist two common selling formats: a wholesale model and an agency model. In the wholesale model, the e-seller transfers products to the platform at a certain wholesale price, and the platform resells the products to consumers. In the agency model, e-sellers sell products directly to consumers through the platform and pay service fees to the platform. In practice, different e-commerce platforms adopt different online review systems and selling formats. For example, Taobao, who adopts the agency model, divides the online reviews into good, medium and bad reviews in the online review system, while Vip.com, who adopts the wholesale model, and Tmall, who also adopts the agency model, use "star" to evaluate products, which blurs the concept of good and bad reviews. On the other hand, for e-sellers, product quality is a key aspect of consideration when consumers purchasing a product. In brick-and-mortar stores, consumers can experience products and identify product quality immediately. However, it is difficult for them to obtain the accurate quality information when shopping online, hurting the trust between e-sellers and consumers. Consequently, it's reasonable to ponder whether online reviews truly enhance the quality of products on e-commerce platforms and if so, what mechanism drives this impact. Moreover, one might also wonder about the effect of online reviews on the sales model decisions of e-commerce platforms. To answer these questions, this study examines an e-commerce supply chain composed of one e-commerce platform and two e-sellers. Both e-sellers market their products through the platform, the two products are partially substitutable. We consider two sales models: a wholesale model and an agency model and further assume two types of consumers exist: loyal consumers, who consistently buy products produced by a particular e-seller, and general consumers, who choose between two products according to their own utility, considering both the quality and fit attributes of the products. We use the Hotelling model to describe the fit attributes of products and assume that e-sellers determine the product quality attributes. Enhancing product quality incurs a cost to the e-sellers. To encapsulate the characteristics of online reviews, we further assume that consumers lack precise information about product quality and fit. However, they can access this information through online reviews and infer product attributes based on these signals. We derive the products’ demand function from the consumers’ utility function and derive the profit functions of e-sellers and the e-commerce platform. These functions serve as the basis for our dynamic game model between the platform and the two e-sellers. The first step of the game involves the e-sellers setting their product quality. The second step involves setting the wholesale price (wholesale model) or profit margin (agency model) of the products according to the sales model. In the final step, the product price is set by either the platform (wholesale model) or the e-sellers (agency model), depending on the sales model. We obtain a closed-form equilibrium solution for the game using backward induction. Based on the equilibrium solutions, we compare the equilibria of different models and use a comparative static analysis to examine the impact of online reviews on the quality, price, and sales model of the e-commerce supply chain. The results show that online reviews intensify the quality competition among e-sellers, compelling them to improve product quality and increase consumer demand. However, if the competition between e-sellers is too fierce, the increased consumer demand cannot compensate for the loss incurred by e-sellers in their quest to improve quality. Hence, online reviews may undermine the efficiency of the e-commerce supply chain. Furthermore, online reviews can alter e-sellers' preferences for sales models, which subsequently affects their choice of platforms. This study provides novel managerial insights. E-commerce platforms need to design their commenting systems in alignment with their strategic positioning. For platforms focusing on product quality, enhancing the information quality of the comment system is necessary. Conversely, if the platform's strategy emphasizes cost-effectiveness, reducing the information quality of the comment system may be the optimal decision. For e-sellers, if the cost of improving product quality is relatively low, they need not necessarily enhance the information quality of online reviews.