Ian A. Kash, John K. Lai, Haoqi Zhang, and Aviv Zohar
Many private file-sharing communities built on the BitTorrent protocol require members to maintain a minimum ratio between uploads and downloads, effectively establishing credit systems, and with them an economy. We report on a half-year-long measurement study of DIME, a community for sharing live concert recordings. While the download of files is priced only according to the size of the file, we observe significant disparities in the rate of return for seeding new and old files. By consuming and subsequently seeding new files, visitors can quickly earn credit, while old files offer lesser returns. Factoring in the potential gains from seeding, the resale value of files of the same size is no longer uniform. We provide evidence that users react to these differences in resale value by preferentially consuming older files during a ‘free leech’ period.
In 6th Workshop on the Economics of Networks, Systems, and Computation (NetEcon)