Possible Clues:

• Customer from America coming in closer
• Retail computer buyer, e.g.
• Customer who smokes others' fags?
• Software buyer, usually
• Employer chasing objective consumer
• Ultimate recipient of goods suffers when last three turn up
• Receiver of product puts up with three bits the wrong way round
• Ensured result for last to get product
• Customer's rudeness briefly troublesome
• Consumer bears last three back