1. A sales portal system supporting a plurality of buyer computers used by a corresponding plurality of buyers, the sales portal system comprising: a server system communicatively coupled to: a first seller's computer used by a first seller to support sales of a product, the product having a first description and a first price, both the first description and the first price being stored in a first database of the first seller's computer; a second seller's computer used by a second seller to support sales of the product having a second description and a second price, both the second description and the second price being stored in a second database of the second seller's computer, and the first seller being a competitor of the second seller; and the plurality of buyer computers, wherein: the server system responds to a query received from one of the plurality of buyer computers by both delivering a first seller rating and a second seller rating, and delivering the first description and the first price and the second description and the second price respectively from the first database and the second database, to the one of the plurality of buyer computers; and the server system managing a sales transaction of the product from one of the first seller and the second seller as identified by the one of the plurality of buyer computers.