This is a sponsored post. As if learning how to rent out your unused space for cash, as well as stay on-the-cheap at other people’s unused spaces around the world, wasn’t enough, Airbnb is going the extra mile for Shanghaiist readers. We already taught you how to become an Airbnb member, now here’s a sweet coupon. Enter “SHANGHAIIST” upon your Airbnb membership and you’ll get $60 USD off your next rental. The coupon expires Aug 15, 2011… so act fast!