Competitive Marble Racing
Dion Bakker and his brother Jelle started a YouTube channel in 2006 posting videos of marbles racing down tracks. Marble racing started catching on and slowly the channel gained a lot of popularity. So when all competitive sport was brought to a halt and Olympics got postponed in 2020, the followership of Marbula One and Marblelympics just went through the roof.
Lesson: Follow your crazy little interests AND find a way to document them. You never know when you’ll be in the right place to capitalize on them.