<p>Pop-up stores have emerged as a key innovative model in the fashion retail industry because of their ephemerality and distinctiveness. Despite significant interest in the allure of pop-up stores, systematic investigations into how the specific elements of ephemerality influence consumer behavior remain scarce. This study integrates the dimensions of time limitedness, product quantity scarcity, and experiential exclusivity to examine how these aspects of ephemerality influence consumer reactions through perceived uniqueness, including in terms of electronic word-of-mouth, purchase intention, and brand loyalty. This study, which targeted Millennial and Generation Z consumers, involved the collection of 345 valid responses, and structural equation modeling and multigroup analysis were employed for validation. The findings identify experiential exclusivity as the most crucial driver of perceived uniqueness, followed by time limitedness and product quantity scarcity. Perceived uniqueness significantly predicts positive outcomes in terms of eWOM and PI, although its impact on BL is less pronounced. Multigroup analysis further reveals that social media usage moderates the relationship between ephemerality and consumer reactions, thus leading to significant differences in path relationships across varying levels of usage. This research validates the mediating role of PU in this context, extends the applicability of scarcity theory, and offers practical implications for efforts to develop precise marketing strategies for pop-up stores.</p>