The opposite experience is also disappointing: once I bought a book with 1-click at Amazon (I was probably trying to find out how much the shipping cost would be) and was very surprised that it was really one "no confirmation, your money just went away" click. I'm very afraid of that button.
iirc, for certain sellers you can cancel your order within a certain grace period. The 1-click could have an "undo" option to more easily revert if you didn't mean to click it.
But then they'd probably lose money from the people who impulsively click and regret.
