The article explores four different images of the relationship between market economy and gift economy drawn from economic sociology and anthropology. Second, it presents a case study of an office hotel, which experimented with the relationship between markets and gifting by urging the companies it hosted to share knowledge and commercial contacts. Drawing on Callon's notions of framing and overflowing, the article shows how various interactions ('overflows') either displaced, supported or reinvigorated the boundaries between market and gifting at the office hotel. It notes that these overflows characteristically involved the sharing of access to interactional spaces and information about interaction partners. Finally, it suggests that a particular form of politics of exchange comes into view in the empirical case. This politics centres on the discovery of pragmatic and relatively benign forms of parasitism between modes of exchange.