[hocuspocus]

As far as I understand, Curve is viable due to the fact they issue corporate cards (you can see "for commercial use only" on their cards).

Europe has capped interchange fees to 0.2% and 0.3% for debit and credit cards respectively. However, three-party schemes (like Amex) and corporate cards are exempt and charge more. But you're right, I'm not sure how MasterCard is happy with that (since the product is clearly targeted at consumers).

[abalone]

I see, so they're charging merchants high corporate card interchange and then recharging the consumer card. Yeah, that's sketchy. I wonder if they're pocketing the difference.