Until now, you could not purchase an iPad with cash. Instead you had to swipe a credit card and make it easier for Apple to make sure that you're obeying the two-iPads-per-person limit. Things changed though, because of one woman.
Diane Campbell.
Campbell saved up the money to purchase one of Apple's latest offerings but was turned away because she wanted to pay in cash. In theory, such a payment would make it more difficult for Apple to prevent iPads from being purchased simply for the sake of resale:
"Mr. Jobs, give a sister a break," said Campbell. "I'm not going to go sell my iPad."
And Mr. Jobs did give her a break according to ABC:
As of today, anyone can pay for an iPad with cash as long as they set up their Apple account at the store. Apple accounts are needed for the iPad anyway, so that is not putting anyone out.
There was also an explanation that "grey market" resales weren't the real reason for the no-cash policy, but rather that Apple simply wanted to make sure that iPads were evenly distributed among stores to meet demand.
Now, not only was Apple sales policy changed for everyone and explained, but Campbell also received a free iPad for reminding Apple of how much more money it could make by actually accepting cash. [ABC]