When I was 15, I made a video called "Paper iPod touch," which was a stop motion animation that made it appear as if I was interacting with an iPod touch by pressing on paper. The video got thousands of hits within its first few weeks, which was more views than all my other videos combined had received up until that point.
In the video, there's a part where I press the play button inside the music app, and a song starts playing. "Satellites" by the band Sounds Under Radio was my favourite song at the time after hearing it in the War Games 2 soundtrack, so naturally I chose that song, expecting to get under 100 views on the video anyway. When the video had around 10,000 views, YouTube contacted me and asked if I'd like to place advertisements on the video to make money from it.
Unfortunately I knew that I couldn't legally do that without the band's permission, so I tracked down their website and sent their band manager an email. He responded by saying that the band loved my video, but that they couldn't give me permission to use it commercially. He added that he had a special proposition for me: the band had a new album coming out soon and they wanted me to make a video for one of their songs!
As a 15 year-old who had just recently started posting YouTube videos, this was probably the best outcome I could have asked for. I'm still very grateful that a band all the way across the world trusted a 15-year old with the official video for one of their new songs.