This chapter discusses customer expectations of services. It explains that customers have two levels of expectations - desired service which they hope to receive, and adequate service which is the minimum level they will accept. The zone of tolerance exists between these two levels. Factors like personal needs, service intensifiers, perceived alternatives, and situational factors influence customer expectations. Explicit and implicit promises made by companies as well as word-of-mouth and past experience shape what service customers predict and ultimately perceive. Understanding customer expectations is important for service marketers to manage perceptions and deliver quality.