It’s invisible to you but each time you swipe your credit card, a fee fairy gets its wings. An interchange fee fairy, to be exact. How does it work? This chart from the Government Accountability Office attempts to shed some light on the murky world of merchant processing fees. Did you know that over the past 10 years, while the technological costs of processing transactions has gone down, interchange fees have more than doubled? A cost that then gets passed on to you in the form of higher prices.