Abstract
BitTorrent is currently a de facto standard for scalable content-distribution. However, its peer-to-peer model for resource allocation does not provide high availability and its performance depends on best-effort contributions given by peers. This has motivated several content-providers to use a hybrid model in which they operate a superpeer in order to attain a higher quality of service. In this paper, we use BitTorrent traces and analytical modelling to inves- tigate the cost incurred by such an entity in relation to the benefits it can provide to the system.