Abstract Customer satisfaction (CSAT) is a central construct in theory and practice; yet its role as a strategic resource is often underappreciated. This article synthesizes the conceptual foundations, measurement approaches, empirical findings, and managerial applications of CSAT research. This article defines CSAT as a post-consumption evaluative judgment of whether customers receive the promised value, and distinguishes it from related constructs such as service quality, engagement, loyalty, experience, and value. Drawing on multiple scales and a comparative study across consumer demographics, we demonstrate that widely used CSAT measures exhibit strong convergent validity. A historical review of the evolution of CSAT research highlights the multi-level nature of the resulting frameworks, providing individual-, firm-, and industry-level insights. Furthermore, we use a large-scale dataset of more than 285 million ratings across 1,126 brands to replicate and extend prior meta-analytic evidence and show that CSAT is robustly associated with customer mindset metrics, accounting outcomes, and stock market performance. Finally, we develop micro-, meso- and macro-level conceptual frameworks and outline a forward-looking, multi-level research agenda to revitalize CSAT scholarship and practice.