Emerging new applications demand the current Internet to provide new functionalities. Although many future Internet architectures and protocols have been proposed to fulfill such needs, ISPs have been reluctant to deploy many of these architectures. We believe technical issues are not the main reasons as many of these new proposals are technically sound. In this paper, we take an economic perspective and seek to answer: Why do most new Internet architectures fail to be deployed? How can the deployability of a new architecture be enhanced? We develop a game-theoretic model to characterize the outcome of an architecture’s deployment through the equilibrium of ISPs’ decisions. This model enables us to: (1) analyze several key factors of the deployability of a new architecture such as the number of critical ISPs and the change of routing path; (2) explain the deploying outcomes of some previously proposed architectures/protocols such as IPv6, DiffServ, CDN, etc., and shed light on the “Internet flattening phenomenon”; (3) predict the deployability of a new architecture such as NDN, and compare its deployability with competing architectures. Our study suggests that the difficulty to deploy a new Internet architecture comes from the “coordination” of distributed ISPs. Finally, we design a mechanism to enhance the deployability of new architectures.