This chapter analyses the social organisation of material flows that followed the introduction of extended producer responsibility (EPR) regulation for waste electrical and electronic equipment in Norway. This regulatory scheme, which was originally motivated by environmental interests, was an inadvertent catalyst for the emergence of a competitive market, in which producer responsibility organisations and (inter-)municipal waste management services sometimes have overlapping functions and goals, which can be at odds with one another. This market is characterised by the substantial segmentation and heterogeneity of its participants, which can be seen both in their characteristics, such as size and profit/non-profit motives, and in how they view and enact their roles in the system, the business models they adopt, and how they relate to producers and retailers of electric and electronic products and to incumbent waste-management services. A thorough understanding of the social organisation of material flows problematises the extent to which circular-economy transitions can be driven through targeted regulation, especially of the kind that promotes competition, since by so doing, policymakers miss the opportunity to regulate the value that is created, for whom and how. Our findings suggest that transitions of this magnitude are contingent on the transformation of social institutions, of which regulation is only part of an intricate social whole.