I realize that rapid and efficient service is pretty much your gimmick, and I understand that I was the only customer in the store. And don't get me wrong, I very much appreciate that you've managed the trick of being really fast without it feeling like you're trying to rush me out of the store. I'm a fan.
All that said, the fact that you were handing me my sandwich before I'd managed to put my change in my wallet kind of creeped me out.
PS -- I don't like your website.