A method and system for auctioning a product on a computer network includes an auction site computer having an auction site and a scan site computer having a scan site. The method and system includes placing a desired product identifier on the scan site of the computer network. The desired product identifier is indicative of a product desired by the buyer. The auction site has a sale product identifier indicative of a product for sale by a seller. The auction site is then monitored with the scan site. The desired product identifier on the scan site is then compared with the sale product identifier on the auction site. Whether the product desired by the buyer is for sale on the auction site by the seller is then determined from the comparison between the desired product identifier and the sale product identifier. The buyer is then notified when the product desired by the buyer is for sale on the auction site by the seller. A bid from the buyer is then placed to the auction site for the product desired by the buyer. The scan site may be monitored to determine the product desired by the buyer. Each of the product identifiers may include a category product and/or a description product identifier. Comparing the desired product identifier with the sale product identifier includes comparing the category product identifier on the scan site with the category product identifier on the auction site and/or comparing the description product identifier on the scan site with the description product identifier on the auction site. The auction site may be monitored with the scan site using electronic data interchange (EDI) messaging.