Online retail sales have risen from nothing to about $20 billion. Business-to-business transactions—that B2B thing—have grown to $109 billion. By 2003, Forrester Research estimates, online retail sales will grow to $144 billion, and B2B business e-commerce will jump to $1.3 trillion. (That's just in the United States, folks.)

Later this week the German computer software maker SAP is expected to roll out the first in a series of online markets aimed at key industries. The move is part of SAP's strategy of competing in the rapidly expanding business-to-business (B2B) e-commerce sector. No one can be quite sure just how big B2B e-commerce is likely to become but enthusiasts are already counting in billions of dollars.

The AMA has launched the B2B Marketing Exchange, an Internet bulletin board designed to provide information on coming events, research sites, courses, and articles of interest to business-to-business marketing academics and practitioners.