Auctions are unique in that you can be a valuable customer without ever having spent a dime with the AH. This is because as long as you bid, you raise the overall level of prices and interest. Even if you don't win, someone else has to pay more than they would have if you had not bid. Non-winning bidders are as important to final prices as the eventual winners.
So an AH bidding on its own auctions may do more to help the bottom line when it loses an item than when it wins. That's why it's wrong for an AH to bid in their own auctions, even if they have some intent to try to win and the bidding is done through a technically separate business.
Not that I will stop bidding in H/S.
Jo.ann K!ine