New York Times has two interesting statistics:

An estimated half-million people make a full- or part-time living by auctioning everything from macrame to Maseratis on the Internet. In the online auction world, they are called power sellers, and they have succeeded by researching consumer trends, finding reliable sources for goods and not sparing the bubble wrap.

eBay, of course, is not the only game in town, though it is clearly the largest and most popular Internet auction site. [eBay] has 114 million users, far more than competitors like Ubid.com, Bidville.com and ePier, as well as the auction sections of Amazon.com, Yahoo and Overstock.com.

Note that not all of the half million people making a living with Internet auctions use eBay, though it’s likely that most of them do. The long tail of ecommerce, though in some ways decentralized, still heavily relies on eBay when it comes to Internet auctions.