1. A sales promotion system supporting a plurality of buyer computers used by a corresponding plurality of buyers, the sales promotion system comprising: a promotion server system that responds to a selection of a first product category received from one of the plurality of buyer computers by delivering a first description, a first link, and a first promotion value, related to a first product of a first seller, to one of the plurality of buyer computers; and a secondary server system that responds to the one of the plurality of buyer computers via the first link to deliver a web page to the one of the plurality of buyer computers, the web page relating to the first product.