1.7% for paypal world sellers, and bonus money of 4.7% on working capital. Not to mention the 1.5% cash back on debit card purchases. Trust me - unless you spend a hundred k on adwords, it would be tough to beat paypal in the real world.
Or is Google going to give a dividend on cash setting in your payments account?
However, like Rob said, this has little to do with Ebay and everything to do with Yahoo.
How long will the AdWords bounty last? 2-3 months? I bet it is under 4.