This study develops a theoretically integrated framework that extends the Technology Acceptance Model (hereafter called TAM) by incorporating social proof and fear of missing out (hereafter called FOMO) to explain purchasing behaviour in digital commerce environments. While TAM has traditionally explained technology adoption through cognitive evaluations such as perceived usefulness and perceived ease of use, it offers limited insight into socially induced emotional processes that increasingly characterise online consumption. Addressing this gap, the proposed framework views online platform adoption as an enabling condition that exposes consumers to socially visible cues such as peer reviews, influencers’ endorsements, and popularity indicators, which activate FOMO as an effective response. FOMO is conceptualised as a mediating mechanism that translates social validation into urgency-driven behavioural intentions and purchasing outcomes. Drawing on literature in technology acceptance, social influence, and consumer psychology, this study proposes six theoretically derived propositions linking platform adoption, social proof, FOMO, and purchasing behaviour. By integrating cognitive, social, and emotional dimensions within a unified structure, the framework offers a more comprehensive explanation of technology-mediated consumption. The model contributes to digital marketing and information systems research by reconciling rational and affective perspectives and provides strategic implications for designing ethically grounded, socially engaging online platforms.