I can only speak about the agreement we had with our payment processor. As soon as Visa announced the change to the structure fees, it was passed on to us immediately. It wasn't just a change from the single interchange fee to this grid of interchange fees. There was also the introduction this year of an assessment fee and a foreign transaction fee. So there were other fees that made up the merchant discount rate.
I don't know if anyone at Visa or MasterCard has ever taken a statistics class, because “average” should take into account the weighted average. You can say that, on average, you're charging one fee, but if you've moved all the cardholders to the higher-cost cards, that's no longer the average rate.