The idea to drop leaflets from the air to spread a political message stems from historical methods of leaflet bombs. Filling a bomb with millions of sheets of paper and dropping them from the air so that big regions on the ground get covered with these leaflets and the messages get spread.
Today campaigning is not bound to physical restrictions anymore, with digital tools one can reach nearly every single soul on the planet. With paperstorm we cover the virtual surface of planet earth with sheets of printed paper.