No harm, but a bit of annoyance when some of the better-run sites keep track of the expiration dates of the cards on file and send timely reminders to update the card info before they become invalid. Also, I don't want to deal with having to double-check my card info every time I make a purchase in order to be certain that the particular site in question has indeed been updated. I prefer to do it all at once. Or better yet, not have to do it at all!

tanstaafl.