Museums are participating in the capturing of global data for the perceived benefit of improved relationships with the public. This article proposes a framework for critically analyzing the ratification of museum visitors and visitor engagement, combining a critical lens from data studies with a social view of datafication as practice—a set of practices within a sociotechnical assemblage that is continuously reproduced by the choices made within and outside the museum. Museums are situated at the intersection of PierreBourdieu’s economic, cultural, and political fields; thus, I highlight some of the external social and technological pressures driving datafication in museums. Relying on public accounts and previous case studies, I argue that datafication of visitor engagement is made to work through data loops: circular processes between institutional practices of museums and social practices of audiences where data are collected, processed, and decided upon.