Seoul has the highest gasoline consumption in the world. With parking space scarce, people in Seoul drive around 15km a month to find space for their cars. This is equivalent to 1 Litre of gasoline being used only for parking.
So to help save gasoline, South Korean oil brand, S-Oil teamed up with Cheil Worldwide to devise a new way of telling people that there was a parking space available right next to them. Bright yellow HERE balloons were setup for each parking space. Then as a car parked, the balloon would fall. On leaving the space the balloon would rise again. Hence drivers around could see the colourful balloons from far away and spot the empty spaces without wandering all over.
In just one day, 700 cars used 23 litres less oil. Over a whole year, they saved much more.