They have to give most of that to the credit card companies. I am not sure how much of the 2.75% they get to keep but I would guess less then half, maybe even only a quarter?
It actually is more like $200mm gross (due to discounts, and that's run-rate, not 2012 I think), and then goes to Chase Paymenttech and to the card associations, interchange, issuers via chase -- as well as all their other costs. So I think netting $50mm off the transactions is generous.
They have at least 500 employees -- figure $100k/ea loaded cost, only possible since I think a lot of those employees are not engineers. That's all of it right there.
They really need to be in the 50b/yr range to be doing well. OTOH, they will probably get there in a year or two, and I don't see their costs going up much.
You're pretty close to the mark - at least for a company doing that much payment volume. Maybe closer to 1.8% or so. There's dozens of variables (debit vs credit, issuing bank, network, international, chargeback rates, etc...) so it's hard to say with any reasonable degree of certainty.
