New network technologies are framed as eliminating 'transaction costs', a notion first developed in economic theory that now drives the design of market systems. However, the actual promise of the elimination of transaction costs seems unfeasible, because of a cyclical pattern in which network technologies that make that promise create processes of institutionalization that create new forms transaction costs. Nonetheless, the promises legitimize the exemption of innovations of network technologies from critical scrutiny.
Keywords: blockchain; decentralized market places; fintech; network technologies; technical promises; transaction costs.