As K-pop continues its global expansion, the formulation of data-driven strategic frameworks for digital platforms has become imperative. This study examines the impact of genre atypicality—a primary differentiating factor in K-pop—on global market performance. We hypothesize that this relationship is non-linear and moderated by an artist’s established market position. Utilizing an annual fixed-effects model, the study analyzed approximately 16,000 tracks by Korean artists on Spotify, leveraging objective audio metadata to quantify stylistic deviation. The empirical results reveal a statistically significant U-shaped relationship between genre atypicality and commercial popularity. Specifically, both high genre conformity (low atypicality) and pronounced stylistic innovation (high atypicality) yield greater popularity than intermediate levels of atypicality. Furthermore, this relationship is significantly moderated by market tenure: as an artist’s market presence becomes more established, the positive correlation between high atypicality and popularity intensifies. By applying Optimal Distinctiveness Theory to K-pop’s global branding, this research extends the theory’s reach and offers actionable strategic insights for artists and entertainment agencies regarding positioning across different growth trajectories.