For development of the theory of service, the focus was on the constructs of service. The theory is expanded to encompass the various business models of service and the service encounter including but not limited to guest satisfaction, service quality, service and technology, service system design, and customer relationship management. The theory began with the observed differences in different service settings, the emergence of technology and defining the service experience across multiple sectors. Further consideration is given to the aspects of the service transaction and what constitutes service, where a labor component of a firm’s product has been transferred to the customer. Lastly, self-service and automation are considered in the context of the user experience. Implications for industry application are discussed.