We investigate an electronic marketplace driven by suppliers that survey customer responses, determine market values of products, and sell products. A supplier creates and dispatches a mobile agent to potential buyers. The mobile agent carries with it information about the available stock and the residual price of the product. The objective is to maximize the gross returns to the supplier. The mobile agent constructs a demand curve from the amounts that the customers purchase, and modi es it dynamically at each buyer site, in order to maximize the gross returns.