I'm also familiar with charging the competition, but I don't think it's such a great idea. Why? I don't have a cell phone where I can download the app. I know it's old-fashioned, but I'm sure there are other customers who can't do that. Then there's the fact that the receipt has to be loaded and is only valid for 24 hours, and I know from my circle of friends that many people are annoyed by this restriction. The competition told me that there was no other way.
Migros stick to your system and give your customers the good old paper receipt as before, sometimes 5-fold or 10-fold. I'll then simply have it to hand the next time I shop with you.