Drawing upon utility maximization theory, this study examines the consequences of quick response (QR) code mobile promotion in terms of information privacy concerns, defensive responses (intention to protect, fabricate, or withhold), and loyalty. Two contextual variables, social anxiety and situational involvement, are hypothesized as moderators. The main survey employs the scenario method with 667 general consumers in Japan. The results indicate that most of the main effects are supported for both moderators. There are strong interaction effects of social anxiety and situational involvement in intention to protect and intention to fabricate personal information. Our study suggests that QR code promotion is a practical and useful tool for loyalty, and its use may significantly depend on its context, whether physical or psychological.