Cloud content providers must deliver vast amounts of data to an ever-growing number of users while maintaining responsive performance, thus increasing bandwidth-provisioning expenditures. To mitigate this problem, the authors transparently integrate BitTorrent into the cloud provider infrastructure and leverage users' upstream capacity to reduce bandwidth costs. They also allocate seeder bandwidth optimally among swarms to maximize throughput. Their system delivers higher performance when dealing with large volumes of data compared to the traditional client-server paradigm. The authors' solution has been integrated with OpenStack, a widely used open source platform for cloud services, to provide a personal cloud storage system.