eBay: Filled with things we love, sell, and buy to upgrade our worlds.

Mobile: On the go.

eBay + Mobile = On-the-go upgrades.

To promote the eBay Mobile app, we'll take its ideal of "on-the-go upgrades" and plop it right on the street. We'll buy a classic player piano off eBay, hot-wire it to interact with the app, then encourage passersby to use the app to play beautiful music and upgrade the world for everyone around.