This article challenges common assumptions and opinions regarding the use of the social web by cultural heritage institutions by framing the phenomenon of user-generated metadata within the larger context of the commodification and the engagement process of our cultural heritage. Theoretical reflections on both the negative and positive long-term outcomes of the social web for libraries, archives, and museums are presented and confronted with empirical observations regarding the use of social tagging and user comments. This combination of a theoretical and an empirical approach will provide original insights into the long-term implications of user-generated metadata for cultural heritage institutions.