Elon mentioned it at a speech a while ago. Just not enough people used it. I think it was setup to fail, though. First of all, it took longer than they originally said. You had to make an appointment, so you could not just drive up and expect it to be swapped. That alone was a huge turn off. Having to pay doesn't help either. I think when you have to plan a stop, you go to the bathroom anyways, maybe get a drink, so Supercharging is just fine.