Someone found this gem on the way back machine. I now remember that I once knew but this trivia factoid, but it got pushed back into the archives.
Did you know? https://en.m.wikipedia.org/wiki/YouTube
[T]he original idea for YouTube was a video version of an online dating service, and had been influenced by the website Hot or Not. Difficulty in finding enough dating videos led to a change of plans, with the site's founders deciding to accept uploads of any type of video.