This conclusion weaves together the wide-ranging contributions of this volume by considering data-driven personalisation as an internally self-sustaining (autopoietic) system. It observes that like other self-sufficient social systems, personalisation incorporates and processes new data and thereby redefines itself. In doing so it redefines the persons who participate in it, transforming them into ‘digital’ components of this new systems, as well as influencing social arrangements more broadly. The control that elite corporate and governmental entities have over systems of personalisation – which have been diversely described by contributors to this volume – reveals challenges in the taming of personalisation, specifically the limits of traditional means by which free persons address new phenomena – through consent as individuals, and democratic process collectively.