The likes of QVC negotiate deals with delivery companies and pay much much less per delivery than you or I would. QVC will have a contract with Hermes and Q will pay a yearly lump sum which gives Hermes a much needed large cash injection but it also means QVC are having many thousands of deliveries fulfilled for a cheap price per delivery.
One of my sons works for UPS and they do much the same, as do most delivery companies and they`re all trying to undercut each other in order to get the large contracts.
For example where we`d pay £4.95 for a delivery, it would cost one of their contract companies much less. The more QVC sells then the less per delivery it costs them so something such as this LE tsv which has sold in thousands will work out costing them a pittance for delivery.