Research on customer relationships has documented that customers focus not only on the functional benefits they receive, but also the relational benefits. This study examines the underpinnings of customer relationships designated as professional relationships, casual acquaintances, personal acquaintances, and friendships, with regard to the relational factors: emotional attachment to a particular provider; personal advice seeking, and socializing outside of the service encounter. A survey is used to examine relationship types across four service industries (healthcare, financial services, hair care, and automotive repair). It is found that relationship types can be distinguished based on the relational factors, and that relationship types vary by service.