Business models involving buyers of digital goods in the distribution process are called superdistribution schemes. We review the state-of-the art of research and application of superdistribution and propose a systematic approach to market mechanisms using super-distribution and technical system architectures supporting it. The limiting conditions on such markets are of economic, legal, technical, and psychological nature. Large scale applications of superdistribution such as video-on-demand and multimedia over peer-to-peer type networks pose particular requirements on security and efficiency.