Surprise marketing is a deliberate strategy involving the introduction of unexpected and/or uncertain elements (e.g., unexpected coupons, mystery box) into the customer shopping journey to evoke strong positive emotions. Despite its widespread use, academic research lacks a comprehensive understanding of its intricacies. This study addresses this gap by delving into four crucial dimensions-what, how, why, and when-to provide a more profound comprehension of surprise marketing, define the concept, and delineate its fundamental characteristics. Building on both theoretical literature and real-world business examples, the authors identify curiosity and attribution as mechanisms that initiate four mediating paths: excitement, anxiety, gratitude, and skepticism. These paths underscore the tensions underlying surprise marketing that also shape marketing outcomes across shopping stages and lead to both favorable and adverse effects. Reflecting these inherent dynamics, this study introduces five managerial moderators-surprise stimulus type, surprise stimulus value, surprise complexity, customer loyalty type, and distribution channel-that can either amplify or reduce the dynamic effects of surprise marketing. These boundaries of its influence reveal managerial pathways to achieve favorable outcomes. This article concludes with managerial implications and research directions to advance pioneering trends in surprise marketing practices.