Editor's note: Smart Business explores the ways companies are thinking smart to thrive in our digitized world.
(CNN) -- Social media is revamping the way businesses reach their audiences, transforming boring billboards and cold commercials into a land of interactive wonders.
Here we collect some of the best new examples of companies using advertising to get social with customers, including coffee company Douwe Egbert, which created a yawn-activated drink dispenser in a Johannesburg airport using facial recognition technology, and the frozen food firm Birds Eye, which created a pop-up called The Picture House in three British cities to allow diners to eat for free in exchange for sharing a snap on Instagram.
And on London's busy Oxford Street, people who walk past the bus stops don't realize they're a step away from a free snack at one of the special vending machines there. The dispensers are run by Walkers, which is known as Lays in the US and Chipsy in Egypt.
Anyone who passes the machines can send a message to Walkers on Twitter and out pops a free bag of a new line of potato chips chosen by the public. (Sample flavors: Ranch Racoon and Chip Shop Chicken Curry).