How do you add value to something that's free?

McDonald’s wanted to promote their Blended Ice Drinks by giving them away every day over the summer.

Previous giveaways had seen massive online sign up, but only a handful of people actually going into restaurants to redeem. So we decided to make the voucher feel a bit more valuable by putting up a small barrier to entry. Something which meant you actually had to engage with the brand and earn the free drink.

We asked people to prove how summery they were feeling by singing along to one of our five second summer songs. Hit enough of the notes and the drink was yours.

That year the number of people going into restaurant to redeem was way up.
But maybe that was just a spooky coincidence...