The customer orientation required in both classical and modern marketing understanding necessitates a fundamental understanding of the relationships and influencing factors of insurance demand. Thus, insurance customers with their needs and their behavior are a central reference point of (empirical) marketing research. Before their approaches and methods are presented (Chap. 5), the demand behavior of private insurance customers is first discussed theoretically. Although many of the theoretical explanations presented subsequently apply to private, commercial, and industrial customers, the focus of interest here is on a better understanding of the insurance demand of private customers.