It’s summer in the UK. Two cigarette disposal bins are erected on a littered street. One bin is marked Ronaldo, the other, Messi.
The bins encouraged smokers to vote for the best football player with their cigarette butts. After twelve weeks, cigarette litter dropped by 46%.
Instead of yelling at smokers to “clean up your butts,” the bins implied the desired behavior in an easy and fun way. That’s a nudge.