This chapter reviews the literature on the social effects of emotions in the context of customer service and consumer behavior. The first part of the chapter reviews research on the effects of service providers' emotional displays on the emotions, product attitudes, purchase intentions, and actual behavior of consumers. In this context I also discuss work on emotional labor and the perceived authenticity and appropriateness of service providers' emotional displays. Reversing the focus, the second part of the chapter addresses research on the effects of customers' emotional expressions on service employees' emotions, job satisfaction, wellbeing, cognitions, and performance. In the third part of the chapter I review studies on the effects of emotional expressions on the effectiveness of persuasive communications. The fourth part is devoted to emerging research on interpersonal emotion regulation in customer service. The final part of the chapter addresses the role of emotional intelligence in the service industry.