This is a long running offer which seems to be permanently on the app. you dont need to be a Virgin customer in any way to get the app. you can use unlimited times. you still get at least one loyalty stamp too. It generates a code at the till. If it says you've used it, don't worry you can go back and click it again and it works - I had this problem today. There are no franchises with Nero unlike other chains so should work everywhere.