Open-domain chatbots engage in natural conversations with the user to socialize and establish bonds. However, designing and developing an effective open-domain chatbot is challenging. It is unclear what qualities of such chatbots most correspond to users' expectations. Even though existing work has considered a wide range of aspects, some key components are still missing. More importantly, the consistency and validity of the combined criteria have not been tested. In this paper, we describe a large-scale survey using a consolidated model to elicit users' preferences, expectations, and concerns. We apply structural equation modeling methods to further validate the data collected from the user survey. The outcome supports the consistency, validity, and reliability of the model, which we call PEACE (Politeness, Entertainment, Attentive Curiosity, and Empathy). PEACE, therefore, defines the key determinants most predictive of user acceptance. This has allowed us to develop a set of implications useful for the development of compelling open-domain chatbots.