McDonald did a great little advertisement campaign using an interactive billboard in Stockholm (Sweden). The interactive billboard challenged anyone to play a game of pong to win free goodies from McDonald. Anyone with a smartphone could goto their website and the online app confirmed that the geo location from phone, confirming if you were in vicinity of the billboard. And then the game starts on both the phone and the public billboard. If you win the game, it gives you a digital coupon as well as instructions on your screen to reach nearest McDonald to claim your free snack. Ingenious advertisement! check it out in video below.