If you want to watch videos from certain YouTube channels, you're going to have to pay up.

As expected, the Google-owned video-sharing site on Thursday launched paid channels as part of a new pilot program that gives content creators a new way to earn revenue from their videos. There are currently 53 paid channels participating in the pilot, including National Geographic Kids, UFC Select, and British TV provider Acorn TV.

All paid channels offer a 14-day free trial, but users will need to pay a subscription fee to keep watching beyond that period. Subscription fees start at $0.99 per month, though it appears most paid channels are priced higher than that.

The UFC Select channel, for instance, is priced at $5.99 per month and provides access to full event replays, classic fights, and full episodes of UFC shows such as UFC Unleashed. Sesame Street is also planning to launch a paid channel offering full episodes, according to YouTube.

"Today, there are more than 1 million channels generating revenue on YouTube, and one of the most frequent requests we hear from these creators behind them is for more flexibility in monetizing and distributing content," the YouTube team wrote in a blog post.

Once you purchase a subscription to a paid channel, you'll be able to watch the videos on your computer, phone, tablet, and TV. At this point you can only subscribe to channels from a computer, but you'll soon be able to do so from other devices.

"This is just the beginning," YouTube said. "We'll be rolling paid channels out more broadly in the coming weeks as a self-service feature for qualifying partners."

Rumors about such a service began swirling in late January, pointing to subscription-based access to certain YouTube channels, which would cost between $1 and $5 a month, and be created by media outlets that already have large followings.