Never underestimate the power of simple fun. Coca-Cola celebrated Friendship Day by building a 3.5m-tall vending machine with a twist. The only way to get the extra free Coke was to reach the coin slot by climbing on top of someone else’s shoulders.

The Friendship Machine, from O&M and Geometry Buenos Aires for Coca-Cola.

Can you design an experience everyone feels compelled to play with?

Can some elements not be revealed to engage people’s natural curiosity?