This chapter examines how darknet drug marketplaces operate within platform capitalism. While capitalist power relations remain underexplored in research on digital drug markets, the analysis shows that the basic foundation of cryptomarkets relies on the infrastructure of platform capitalism. The authors use the concept of platform capitalism to explore cryptomarkets in an ideology-critical way. Platforms are infrastructure for the mediation of buyers and vendors; however, they are designed to extract data on the activities of their users. Platform capitalism refers to the process by which the vast collection of user data feeds into the accumulation of capital. The authors use a dialectical method to examine the constellation of digital drug platforms by disclosing a threefold contradiction: state control and self-regulation; visibility and concealment; and legality and illegality. The analysis reveals that darknet drug platforms make a profit not only from the trade of illicit drugs and the collection of user data, but also based on the illegal status of drugs, the associated ideology, and the closed ecology of darknet platforms. Power relations in cryptomarkets thereby mimic those observed in platform capitalism in general. Finally, the authors discuss the implications of platform capitalism for online drug markets.