Like so many big stories, Caitlin Crosby’s starts small. At first, she just had an affinity for wearing old keys as necklaces—keys that she’d engrave with inspiring words. The keys, she says, were a reminder of what most people are like: unique, flawed, discarded, but not without purpose.

The idea started to take off when Crosby met Rob and Cera, a homeless couple who specialized in making jewelry. She hired them to help her make key necklaces the very next day, and that’s how The Giving Keys was born.

Since it started, The Giving Keys has employed 13 people going through homelessness, who make their signature key necklaces for over 300 stores worldwide. Anthropologie carries them. Fred Segal carries them. They’ve been spotted on everyone from Ryan Gosling to Taylor Swift. It’s a bonafide trend, but it runs deeper than a fad.

The idea is that the words engraved on the key can be passed along to people in emotional need, just like the business itself is run by people in physical need. The keys—engraved with words like strength, courage and love—can be passed along to friends in need of encouragement. Crosby’s story has now multiplied into these many, many other stories—hundreds of which are posted on The Giving Keys’ website.

The idea of “story” is common in millennial entrepreneurship, but it’s still rare to see someone take the idea so seriously. Crosby has built the idea of her own narrative deep in the framework of her business—so deep, in fact, that it’s taken root and is starting to flower.