YouTube is making original shows with celebrities like Ellen DeGeneres, Kevin Hart, and Katy Perry - here are the details

Significantly, these shows will live on YouTube's main ad-supported service, and not on its $9.99-a-month subscription service, YouTube Red. That means they will be free for everyone to watch.

Why is YouTube tapping these stars now?

"Five years ago, 85 percent of all original series were ad-supported," Robert Kyncl, YouTube's business chief, said Thursday. "This year, that number has fallen to just over two-thirds. And with significantly more content coming to subscription services, that shift is accelerating. So we see these shows as a way for us to partner with [advertisers] to buck this trend."

Kyncl said Johnson and Johnson had already signed on as the "exclusive sponsor" of one of these new shows, Ryan Seacrest's competition show called "Best.Cover.Ever."

But enough about the business strategy, what are the shows? Here is a list of the ones YouTube announced on Thursday, along with their description: