Specific investments, which are tailored to a particular company or value-chain partner, are important components of firms' marketing strategies. At the same time, extant theory suggests that such investments pose considerable risk, because they put the receiver in a position to opportunistically exploit the investor. In this article, the authors examine this "expropriation" scenario but also consider whether specific investments, because of their specialized nature, may actually "bond" the receiver and reduce opportunism under certain conditions. These conditions involve a focal relationship's time horizon (i.e., its extendedness) and particular norms. The key theoretical argument is that the effect of specific investments on opportunism will shift in a nonmonotonic fashion over the range of these relationship conditions. The authors test their research hypotheses empirically through parallel analyses on each side of 198 matched buyer-supplier dyads. The empirical tests provide general support for the predictions but also reveal differences between buyers and suppliers regarding the focal effects. The authors discuss the implications of the findings for marketing theory and practice.