An economic sociology approach grounded in an empirical study of second-hand sporting goods stores is used to examine ‘intermediation' in used goods markets and its impact on confidence-building in market relations. Neo-institutional economic interpretation is contrasted with interpretation that uses a Goffmanian microsociological approach. The first type emphasizes the development of market credibility, analyzing the cognitive and formal arrangements (contractual and technical) which, by ‘professionalizing' the behavior of self-improvised salespeople, reduce both ‘market opacity' and the threat of opportunistic behavior. The second shows that such analysis is insufficient for understanding how actual relations in the marketplace are maintained. It aims to describe how partners to a transaction co-produce confidence, using their social skills and signaling honesty by the way they allow the quality of second-hand goods to be assessed. The two approaches converge, however, in that they both involve recognition of the limitations of analysis in terms of personal networks and the impersonality of economic transaction determinants. The article concludes by calling for closer attention to social relations in the marketplace and greater focus on how those relations are depersonalized.