The provision of services after goods have been sold which make them more useful to customers. This can include advice on and training in the use of the product; routine maintenance, servicing, and repairs in the event of breakdown; provision of materials and spare parts; replacement under warranty in the event of failure of the goods supplied; and updating if the product is developed further. Customers’ expectations of cheap and efficient after-sales service are of great importance in making products competitive, and lack of customer confidence in the quality and price of after-sales services may make products unsaleable. See also competitiveness.