Abstract: A system for selling products on-line including a seller module providing functionality for offering a product, establishing a minimum price for the product, and establishing at least one of a target price higher than the minimum price, and an offer expiration date; a transaction engine publishing the offering of the product; and a buyer module, providing functionality for purchasing, by potential acquirers of the product, rights to participate in a draw for the product; and wherein the transaction engine is operative to automatically conduct the draw in accordance with criteria which include purchase by potential acquirers of rights for a total amount not less than the minimum price, and arrival of offer expiration date or purchase by potential acquirers of the product of rights for a total amount which is not less than target price, and wherein transaction engine is also operative to award the product to winner of draw.