Drawing upon prior research on Internet information privacy concerns, this study examines the effects of perceived ubiquity on consumers’ acceptance of mobile advertising. We postulate that, due to increasing unethical information practice, ubiquity can be perceived both positively and negatively, exercising complex effects on trust, risk, attitude, and intention to delete the ad. With 510 Japanese general consumers, our findings indicate that perceived ubiquity significantly strengthens trust and attitude toward the ad, while none of the negative effects are confirmed. Perceived ubiquity is therefore generally accepted as a favorable utility of mobile communication, leading to more likely acceptance of the ad it delivers. In closing, theoretical and managerial implications are discussed, and important limitations are recognized.