On any given day there are more than 12 million items listed for auction at eBay, the world's largest online trading community. In the year 2002, almost $15 billion worth of merchandise, in more than 638 million individual auctions, was traded over eBay. That's $50 million a day—or $579 every second.

So who's making all that money?

While most eBay users are simple hobbyists, a surprisingly large number of users sell enough items to actually make a living from their eBay auctions. Officially or not, these users are running eBay businesses. They purchase inventory, market their products, collect payments, and ship merchandise, just like an or L.L. Bean does. They're businesses, pure and simple, that operate on and through ...

Get Absolute Beginner's Guide to Launching an eBay Business now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.