Date Added: Feb 2011
Empirical data shows that in the absence of incentives, a peer participating in a Peer-to-Peer (P2P) network wishes to download content, while avoiding to contribute content in return. This phenomenon, known as free-riding, has been actively studied in the literature and incentives have been proposed to compel self-interested peers to cooperate with each other and contribute their content to other peers in the network. Most solutions for providing incentives in P2P networks are based on direct reciprocity, which are effective in networks where the peers are interested in the same content (e.g. downloading a large file such as the Linux operating system).