It is a fair bit, but for any credit or debit card transaction they’re actually taking on the risk of essentially fronting the cost of the transaction. Well really their partnering bank does, but if something happens they’re left covering that cost. They also have to split the profit with their collaborating bank and possibly the credit card companies. Nowadays I suspect the risk isn’t all all that high, or at least not 2.9 less slim profit margin high. So in the end 2.9% isn’t highway robbery but they’re also not working on slim margins.