Upselling is a sales technique where a seller encourages a customer to purchase a more expensive item or add additional features to their original choice. This strategy aims to increase the overall value of the sale while enhancing the customer's experience by offering them better options that may suit their needs. For example, when buying a smartphone, a salesperson might suggest a higher model with more storage or a protective case. By presenting these options, the seller hopes to boost the sale's total while providing the customer with products that offer greater benefits or satisfaction.