The eight articles in this ebook indicate that customer relationships in the financial service sector are complex and demanding. The provider perspective of customer relationships involves to a higher extent creating relevant service offerings based on longitudinal customer insight. Also the customer-provider dyad involves new challenges such as monitoring and acknowledging passive and weak customers. The customer context—what customers do and experience in their own lives and businesses beyond service offerings—is a particular challenge since it is beyond the scope of most financial service providers. Whereas some strategies for maintaining customer relationships can be based on adjusting service offerings and internal processes, many aspects of customer relationships are beyond the control of financial service providers. Such uncontrollable elements in customer relationships are mostly a result of customers' idiosyncratic behavior.