Service-dominant (S-D) logic, a service-centered orientation that reframes the purpose and process of economic exchange, has developed over the last 15 years into a metatheoretical framework that advances a systemic understanding of value co-creation. This chapter traces the evolution of S-D logic, summarizes its core ideas, and compares it with other related perspectives. The broad applicability of S-D logic and its service ecosystem view is discussed along with the implications for service research, marketing, and other disciplines. In particular, this chapter highlights how S-D logic can help service researchers to break free from ‘services’ as a context or a sector and build a more contextual, multi-actor view of exchange.