Let multiple buyers bid competitively for products from individual suppliers. Suitable for hard-to-move goods such as used capital equipment (forklifts) and surplus or excess inventory. Prices only move up, but buyers can buy below list prices while sellers sell for more than a liquidator pays. Auctions are becoming a feature of many Net markets, but some use auctions as their primary market mechanism. Examples: AdAuction, TradeOut.com (used equipment).