When a customer visits a local retailer to buy furniture. They are able to benefit in some cases from the additional service of having the furniture installed for them. At the same time hopefully they will get a good 'service' from the retailer, who will be happy to help them with advice about the properties of different types of furniture, repayment terms, delivery etc. If an oil company assumed that the function of its retail network was simply to sell petrol and lubricants it would quickly lose business to competitors. Its real function is to supply a 'customer service' in its case the service of enjoyable, trouble-free motoring.