The use of the Internet to facilitate commerce among companies promises vast benefits: dramatically reduced costs, greater access to buyers and sellers, improved marketplace liquidity, and a whole new array of efficient and flexible transaction methods. But if the benefits are clear, the path to achieving them is anything but. The B2B market is still in its infancy, and its structure and players remain in rapid flux. Despite breathless press coverage, very little is known about how business-to-business commerce will evolve on the Internet.