Picture this: your target audience is not a group of people, but the one and only mayor of Barcelona.

That was our challenge when Airbnb's explosive growth in Barcelona was causing a ruckus. With traditional tourism taking a hit and lawmakers scrambling to regulate, we needed to show Ada Colau that Airbnb is 100% committed to the city and promotes responsible tourism.

And how did we do it? By teaching Airbnb a word that is so quintessentially Barcelonian that it defies translation.