Tobold explains that the system is actually designed so that players will be more than likely to choose the buyout rather than play the bidding game. Part of this comes from the fact that to not have an item sell is to lose the down payment we place on it when a bid is first posted. With the Auction House as it is currently designed the bidder gets no sense of the bid prices, of the history of bids, of really any of the information that someone might see on an auction site like eBay. It's actually too transparent for the purpose as an auction system.
There have been suggestions as to how this might be improved. Perhaps, like Tobold says, tweaking the interface so that the auctions have more information provided might work. Reader Joe Szilagyi wrote in with a different suggestion. He mentioned the possibility of making the AH like the PvP system, system-wide rather than server-specific. He explains that this would be a way to bolster the economies of lower population servers while at the same time allowing loot to be available to both the Horde and the