Disclosed is a method and system for effectuating a buyer-driven and buyer-executed commerce system. The system allows prospective buyers and sellers of goods and services to anonymously exchange conditional Requests For Bids and Conditional Sales Offers based on the buyer's guaranteed ‘purchasing loyalty’ for a self-defined minimum quantity of goods or services, and/or quality of goods of services and/or the length of time or price to which the buyer would agree to be bound or any combination of those condition's. That buyer guarantee permits a seller to easily pre-determine their offers based on the calculated value of ‘capturing’ that buyer's ‘guaranteed purchasing loyalty’. In a preferred embodiment, the method and system of the present invention includes a controller which receives Requests For Bids from prospective buyers and also receives, stores and displays to prospective buyers, bindable sales proposals from a multitude of prospective sellers. Potential buyers are therefore protected from bidding too much and being bound by the bid before having an opportunity to see what the marketplace has to offer. Further, because only the buyer is permitted to bind a seller, the buyer may submit an RFB more than once, changing any or all of the condition's to which he would agree to be bound in order to explore multiple offers from sellers and to better understand how changing one or more of the conditions affects the offers from the sellers.