Factors Influencing Online Purchase Intention in Flash Sales on E-commerce Platforms: Evidence from Vietnam

This study examines the underlying factors influencing consumers’ instant online purchase intention during flash sales on popular e-commerce platforms in Vietnam. Drawing on the Task–Technology Fit (TTF) theory and the psychological concept of Fear of Missing Out (FOMO), the study proposes and empirically tests a research model comprising five factors: flash sales (FS), e-commerce platform features (WF), platform sales processes (WP), FOMO (FO), and perceived risk (PR). Data were collected from 396 valid responses from consumers who have experience purchasing on e-commerce platforms in Vietnam and were analyzed using SPSS 26. The findings reveal that four factors—FS, WF, WP, and FO—have significant positive effects on consumers’ instant online purchase intention. Among these factors, FS exert the strongest influence, highlighting the critical role of time-limited promotional campaigns in stimulating immediate purchasing decisions. In contrast, PR has a negative effect on purchase intention in flash sale contexts. The main contribution of this study lies in integrating the Task–Technology Fit framework with the psychological phenomenon of FOMO to explain consumer purchasing behavior in high-pressure digital retail environments. By combining technological, process-related, and psychological perspectives, the study provides a more comprehensive understanding of consumer decision-making during flash sales on e-commerce platforms.