eBay published a new "active user" metric. The company defines active user as any user who has bid, bought or sold in the trailing twelve-month period, excluding the users of Half.com and Korea's Internet Auction Co. At the end of the third quarter (ending September 30, 2002), there were 24.2 million unique users on eBay.

eBay had claimed twice the number of users, so the new metric, by measuring only active accounts, is a more relevant number. There is still a question of how eBay counts one person with multiple accounts. I asked eBay spokesperson Kevin Pursglove how I would be counted if I actually had two eBay User IDs, and he gave the following response:

"It is based on the User ID and not the individual. In your case, both User IDs will be considered active if both placed a bid, bought or sold an item in the trailing twelve month period. If you used but one of the user IDs, only that account is considered active."

Half of eBay users have more than one eBay User ID, and 12% have 5 or more eBay User IDs, according to an AuctionBytes survey conducted in May 2001. So while the new number does measure activity on the site, it is not a count of "unique" users. (More information on the survey can be found here: http://www.auctionbytes.com/pages/abu/y201/m06/abu0039/s02.

The new measurement is a step in the right direction. Ideally, eBay would make available number of unique users, and further break it down by international site. It is difficult to measure the growth of the U.S. eBay site, since every time eBay acquires an international site, the number of users is added in to the total.