While business-to-consumer e-commerce (B2C) has garnered the most public attention of any online business sector, business-to-business (B2B) e-commerce is proving to account for a much larger slice of the economic pie. A significant portion of B2B e-commerce transactions will occur through online marketplaces called B2B exchanges. The objective of this technical note is to provide an understanding of these exchanges, including their organizational and revenue models.