The way goods are distributed in auctions affects bidders' surplus and auction revenue. When goods are concentrated among fewer bidders, winners get no surplus. But when goods are spread out, bidders get a surplus that is not zero. Different auction formats matter too. If bidders value items equally, uniform price auctions make more money than discriminatory auctions. If bidders value items less as they get more, uniform price auctions are better. Also, bundling goods can increase revenue even if it's not the most efficient way to allocate them.