This chapter synthesizes extant research on service innovation. It brings together literatures that are typically treated separately, identifying both shared and specific understandings of what service innovation is, and its implications for theory and practice. It begins by reviewing common characteristics, and models of service innovation. After departing in three distinct directions-assimilation, demarcation, and synthesis-it discusses the merits of a fivefold framework to encompass the multidimensional nature of service innovation. Next, following calls for theoretical integration, a typology based on four archetypes is reviewed, and an overarching value-centric view consistent with the synthesis perspective is exemplified. Finally, the chapter discusses why diverse perspectives, despite criticism, continue to exist in parallel. One reason may be that different perspectives emphasize different traits and characteristics of service innovations. Due to the challenges of assessing and managing service development in practice, and operationalization and measurement in research, this divergence is likely to continue in the future. Nonetheless, as service innovation becomes increasingly important across industries, a unifying framework provides both a practical and scientific contribution.