Significant advances in the field of artificial intelligence have given a strong tailwind to the spread of technologies based on it. AI technologies are increasingly influencing private contexts but also the service sector where more and more service encounters are handled by chatbots. In part, however, the spread of chatbots and the associated focus on their functional advantages seem to contradict extant research findings that service interactions are also driven by emotional components. A central role is played here by so-called emotional contagion (i.e., the unconscious transfer of emotions from employees to customers). Against the background that this contagion with positive emotions can lead to a better evaluation of the service transaction in the further course, it is the goal of this book to investigate the effects of positive displayed emotions of a chatbot. For this purpose, six consecutive studies were conducted. The results show that the expression of positive emotions by a chatbot enriches the service interactions by transmitting positive emotions that, in the further course, do also lead to a better evaluation of the service experienced. Moreover, it is shown that these emotional reactions are dependent on the customer’s personality and the chatbot’s appearance, expressed through an avatar.