Could you explain a bit about this? I’ve never seen a card acting double purpose like this and I’d love to read about it. Does your credit card have some sort of rewards program for the store, or is it a store card? Or how does this work exactly?
It's not a store card, it's a fairly regular Visa Credit/Debit card from my bank (Osuuspankki) that has the loyalty card for K Group's stores integrated into it. When you order a new payment card, you can add your loyalty card number in the application and they'll integrate it in your card.
Other banks in Finland also offer the same loyalty card integration with their payment cards.
No idea how it works technically. I assume that it broadcasts the loyalty card and the debit card at the same time when you use NFC, since you can get both with one (long) tap against the payment terminal. It also reads the loyalty card if you use chip + PIN to pay. The loyalty card is completely separate from the actual payment card - if I use Apple Pay to pay with the same underlying Visa card, it will not give me any loyalty rewards.
