Novice eBay users think the auction period is for bidding, and that eBay will make sure that you pay as little as possible. However, in practice only inexperienced people bid early – all others watch the item and try to snipe just before it ends.
So in practice, the auction period functions as a kind of public notice of a future auction, and the actual auction takes place in the last five minutes. However, in contrast to real auctions, the bidding doesn’t stop when there are no more bids, but at a specified time. This is great for experienced buyers with time on their hands, but it’s not great for sellers or inexperienced buyers.
I think it’d be much better if eBay moved to a model closer to real auctions: Announce a week in advance when the auction will start, and then let it run until there has been no more bids for a minute or so. Of course people could still use robots to do the actual bidding for them, but at least everybody would then be bidding at the same time.