This paper studies the value-added services (VAS) investment and pricing strategies of monopoly bilateral platform with limited resources and asymmetric user information. By constructing a game theory model, we conclude that the platform earns higher profits when both of the bilateral users are informed than when the sellers are informed and the buyers are uninformed. The passive expectation of uninformed users weakens the monopoly power of platform pricing and causes lower platform profit. Additionally, the VAS investment and pricing strategies of the platform are jointly influenced by users’ cross-network externality and marginal utility. Among them, the platform investment is mainly related to marginal utility, and its pricing strategies depend heavily on the cross-network externality. Moreover,Uninformed users with passive expectation enforce the platform to invest all of the resources and higher service level in them when the cross-network externality of users on either side does not have a decisive advantage.

研究资源有限、用户信息不对称的垄断双边平台的增值服务（VAS）投资和定价策略。通过构建博弈论模型，我们得出的结论是，当双边用户都知情时，平台获得的利润高于卖家知情且买家不知情的情况。不知情用户的被动预期削弱了平台定价的垄断力，导致平台利润降低。此外，平台的增值服务投资和定价策略还受到用户跨网络外部性和边际效用的共同影响。其中，平台投资主要与边际效用相关，其定价策略很大程度上依赖于跨网络外部性。而且，当双方用户的跨网络外部性不具备决定性优势时，被动预期的不知情用户迫使平台将所有资源和更高的服务水平投入到他们身上。