Buying with credit card......can I borrow money for free, really?

[Jeremy Jackson]

So, I'm on to my next property (buy and hold). I'm wanting to put as little cash as possible up front for the next one. I'm buying in the 10-25k price range. I have two credit cards. Current balance of $0 on both. Credit card A has a limit of 10k, 17.99% APR, currently offering 0% APR on balance transfers until Aug17. Credit card B has a limit of 10k, 11.9% APR, currently offering 1.9%APR on balance transfers until Feb17.

So if I'm gaming this right, I can purchase a 10k property with card B, transfer the balance to card A with 0% interest, as long as it's paid by Aug17.  I understand that the interest skyrockets to 18.9% after Aug17.  I also understand that there is a 3% transaction fee ($300).

What am I missing?  Anyone else doing this?