Selling products online through both auctions and fixed prices can increase a seller's revenue. By offering both options, sellers can attract different types of customers and maximize profits. Consumers who value an item more than its fixed price tend to participate in auctions. The key to success is finding the right balance between auction lot size, duration, and fixed price. Short one-unit auctions and long multi-unit auctions are the most effective strategies, depending on consumer behavior. Overall, using a combination of auctions and fixed prices can outperform just using fixed prices alone, but the seller's profit may be lower if consumers are good at predicting auction discounts.