A system is disclosed for marketing merchandise or services by telephone using brief prerecorded audio demonstrations stored in an audio program repeater and connected to a customer's telephone line by a switching system under control of a data processor in response to a code entered by a customer service operator via the switching system or a code entered directly by the customer through his push-button telephone. In the latter case the data processor is in direct communication with the customer who uses the telephone push buttons to respond to prerecorded messages transmitted from the audio program repeater under control of the data processor. Otherwise the customer communicates with a customer service operator through the switching system and the customer service operator in turn selects the demonstration through the data processor. Having heard the demonstration, the customer indicates whether or not he wishes to purchase the merchandise or services, either to the customer sevice operator, who enters the purchase order in the data processor, or directly to the processor by telephone push-button operation. The data processor then transfers the order to an order processing system and updates both inventory records and the customer's history record.