the_hef:

Good point. There's a way around that, too. If you use the goofy balance transfer checks they send you, interest starts accruing immediately and you get socked with the "transaction fee". This would make it cost-prohibitive.

However, if you call the customer service line, they will transfer the balance over and count it just like a purchase.

So far: 3 months, 15 additional flight credits, not one penny of interest or fees.