i think my buddy has also done the same thing with like a Best Buy card etc; he'll 'buy' a TV with the CC, then go home, log in and pay it off in a day or two. Same thing at Lowes (Lawn mower) etc.
He said something to the effec that he'll use a card for everything he can pay off in full, without penalty. I might be mis-speaking a bit, but you get the idea.
Life is 99% inspiration, 1% Perspiration, and 1% Attention to Detial.