Can AI-mediated Communication Support Purchase Decision?: Evidence from the AI Review Summarization of E-commerce Platform in Cosmetics Industry

This study empirically examines the impact of AI-mediated communication (AMC), implemented as AI-based review summarization, on consumer decision-making in e-commerce and the moderating role of customer loyalty. Online reviews are valuable but often overwhelming, increasing decision complexity and reinforcing the effort–accuracy trade-off. To address this, we analyze whether AMC reduces consumer effort and improves decision accuracy, and whether these effects differ across loyalty segments. Using transaction-level data from a leading Asian beauty e-commerce platform, we employ a difference-in-differences (DID) design and ANOVA analyses. Results show that AMC significantly reduces decision effort, with the strongest effects among low-loyalty customers, while highly loyal customers experience limited benefits. Although AMC does not significantly improve overall accuracy, measured by product return rates, it reduces inaccuracy for low-loyalty consumers by better aligning pre-purchase expectations with post-purchase evaluations. These findings suggest that AMC can mitigate the effort–accuracy trade-off and yield heterogeneous effects depending on consumer loyalty. The study contributes to theory by extending research on bounded rationality and decision support in digital environments, and to practice by underscoring the importance of loyalty-based strategies for maximizing AMC’s effectiveness in e-commerce.