What job was that? Eccles.
Earlier in my career, I worked in Belgium and Luxembourg and I overthrew that policy "of Co only" as to a number of us in the retail petrol business.
This meant that the Co would accept the receipt off nominated staff as to the petrol/desel/LPG rebate they gave all staff (the only Co in the Group that did this). My argument was how in hell are we supposed to know what competition are up to if we dont see/feel/experience their service offerings?
To deny use of other supermarkets, assuming you were with a Sainsburys or Morrisons, or Asda, is a very myopic approach for marketers, Eccles.