It's a Mastercard(Platinium) issued by one of the major gas station chains in Spain. I end up with 10% discount on gas because of it. Though looking the BIN up, I can see some bank is the ultimate issuer of the card, just with branding being that of the gas station chain. I don't have a bank account with the issuer of the card, so they do direct debit from my bank account once a month to cover the minimum payment. A lot of banks allow you to apply for a credit card with them even if you don't have an account with them.

I don't think it's super common to use them day to day as I do. People often use them to split payments for big ticket items. But by using it, I get percentages when buying food and other specific items, so I just run the card and pay it off immediately.