<p>Balancing data utilization and privacy protection is crucial for fostering the sustainable growth of the digital economy. This study examines the role of user anonymized data authorization in the context of monopoly platforms' third-party data integration decisions. The findings reveal that the platform’s decision to integrate third-party data is influenced by the commission rate, the effectiveness of anonymized data in protecting privacy, and the volume of third-party data available. When the platform has amassed a substantial amount of user data and anonymized data provides robust privacy protection, data integration can create a win–win scenario, benefiting both platform profits and user welfare. While data integration leads to a reduction in transaction prices, it enhances market share through precise personalized recommendation services, achieving profit growth despite operating on “thin profit margins.” Users’ decisions to authorize anonymized data are shaped by a trade-off between the negative utility of personalized services and the positive utility of privacy protection. Notably, users are less likely to authorize anonymized data when the platform implementing data integration already possesses a significant volume of user data. For enterprise practice, platforms should calibrate integration scale based on their first-party data coverage and anonymization strength, conducting small-scale, rigorously vetted anonymized data pilots in high-coverage markets, bolstering first-party data collection where compliance costs are high, and employing tiered opt-in incentives to encourage raw data sharing; meanwhile, policymakers should establish clear, graduated anonymization standards and subsidize open-source privacy toolkits to lower compliance burdens and build user trust.</p>