Some of the new middlemen,like eBay Inc. in San Jose,are operating auction sites that use dynamic pricing,a model that exploits the real-time capabilities of the Web to let pricing fluctuate freely based on supply and demand.

• 有些新的中间商，如（加州）圣何塞市的eBay公司经营着拍卖站点，它们使用动态定价，这是一个利用Web的实时功能，让价格随供求关系自由波动的模型。