Dutch coffee vending machine gives away free coffee if you yawn

All you have to do is walk up to the machine, yawn, collect free coffee.

Travellers tired of paying for overpriced airport coffee may want to keep an eye out for Douwe Egberts’ coffee machines the next time they’re flying.
The red coffee dispensers are fairly unassuming and aren’t much smaller than your average soda vending machine. But there’s no need to carry around any pocket change or break a fresh bill because they only take one type of currency: yawns.
Yes, you read correctly: yawns.