There are only ten widgets for sale. So it's not really "why not include the 11th in the winner," it's "why charge the 11th bid and not the 10th?" I think the

There are only ten widgets for sale. So it's not really "why not include the 11th in the winner," it's "why charge the 11th bid and not the 10th?" I think the reason is that everyone feels like they have a good chance of it going for less than they bid (and so they feel happy), but it probably also incentives higher bids.