On Pricing Algorithms for Batched Content Delivery Systems Srinivasan Jagannathan{1}, Jayanth Nayak{2}, Kevin Almeroth{1}, Markus Hofmann{3} Department of Computer Science{1}, Department of Electrical and Computer Engineering{2} University of California, Santa Barbara, CA~93106-5110 {jsrini,almeroth}@cs.ucsb.edu, jayanth@ece.ucsb.edu Networking Software Research Department{3} Bell Laboratories, Holmdel, NJ 07733-3030 hofmann@bell-labs.com ABSTRACT: Businesses offering video-on-demand (VoD) and e-CD sales are growing in the Internet. Batching of requests coupled with a one-to-many delivery mechansim such as multicast can increase scalability and efficiency of resource utilization. There is very little insight into pricing such services in a manner that utilizes network and system resources efficiently as well as maximizes the expectation of revenue. In this paper, we investigate simple, yet effective mechanisms to price content in a batching context. We observe that if customer behavior is well understood and temporally invariant, a fixed pricing scheme can maximize expectation of revenue if there are infinite resources. However, with constrained resources and potentially unknown customer behavior, only a dynamic pricing algorithm can maximize expectation of revenue. We formulate the problem of pricing as a constrained optimization problem and show that maximizing the expectation of revenue can be intractable even when the customer behavior is well known. Since customer behavior may not be well known in an Internet setting, we develop a model to understand customer behavior online and a pricing algorithm based on this model. Using simulations, we characterize the performance of this algorithm and other simple and deployable pricing schemes under different customer behavior and system load profiles. Based on our characterization, we propose a pricing scheme that combines the best features of the different pricing schemes and analyze its performance.