Antitrust scholars have argued that exclusive contracts have anticompetitive, or at best neutral effects, if no efficiencies are generated. In contrast, this paper shows that exclusive contracts can have procompetitive effects, provided buyers are imperfect downstream competitors and contract...

This paper analyzes a two-sided market model in which platforms compete for advertisers and users. Platforms are differentiated from the users' perspective but are homogenous for advertisers. I show that, although there is Bertrand competition for advertisers, platforms obtain positive margins...