86% of people trust brands that share user content. So Skol, Brazil’s top beer, decided to reward the fans who’ve been loyal to the brand for years. We found a loophole on Instagram: you can’t change an old post, but you can edit the caption. So we asked people to add #RetroAd to old photos featuring Skol, turning them into ads. Then we paid them back with what they love most: beer. The older the post, the bigger the reward. And just like that, they became Skol influencers.