Prices are right: managing resources and incentives in peer-assisted content distribution

We present a novel design for a peer-assisted content distribution system that addresses two key shortcomings of existing proposals. First, our system explicitly identifies the relative demand for files: users are rewarded for sharing more popular content. Second, our system efficiently utilizes network resources, by considering resource constraints explicitly when matching downloaders and uploaders. Underlying our system is a market-based mechanism that enables the efficient allocation of network resources across multiple files. Although we price files and employ a virtual currency, these are purely an algorithmic ploy: the system clients hide the market details from the user. Nevertheless, our design also naturally incentivizes the contribution of scarce resources. More importantly, our design endogenously adapts peers’ behaviors to changing environments, a critical advantage for real-world deployments in which network conditions, participation rates, resource demands, and content are continually in flux.