Originally Posted by Fbone
I would think that major web retailers would have safeguards in place to prevent double click purchases. Two purchases in less than a second should always be considered an unintentional error.
When I'm paying bills and ordering things online, sites regularly have windows advising you not to click more than once AND not to refresh the the browser for this very reason.
It's not like there are two orders with the same transaction number that would flag it as being a duplicate. I bet high volume sites process several orders between the double clicks.
It took several readings to understand what happened and I can't see the reasoning behind not wanting your mother to know the second card was a mistake.