Abstract: An online marketplace is established where sellers compete by offering to sell a mass quantity of a specific product, referenced by a unique product ID. A successful sale is determined at a time that maximizes a group of buyers' offers for the specific product. At the determined time, both the sellers' offers and the buyers' offers for the specific product are separately sorted from the lowest price offer to highest price offer. Competing sellers are awarded sales contingent on one or more buyer offers remaining after each seller having a lower sell price is satisfied for its entire quantity. Sells for each successful seller are satisfied starting from a buyer's offer having a lowest buy price and increasing to successively higher buy prices of the remaining buyers' offers, until the seller's entire quantity of the listed product is satisfied.