How a Paris company amassed 220,000 creatives for its brainstorming platform

This is an interview I did with a Parisian company who managed to assemble 220 000 "volunteer" creatives in 148 countries on their platform. What I find amazing about this story is the sheer number of that - 220 000 people, but also the fact that they're relatively unknown. Reminds me a bit of how Pinterest became a giant while hiding in plain sight. I tried to get them to explain their model in as much detail as possible.