LOS ANGELES -- Roger Corman's campy B movies, children's shows like "Sesame Street" and "Inspector Gadget," and inspirational monologues by celebrities -- these are among the offerings on 30 channels that will soon require a paid monthly subscription on YouTube.

Although the world's largest video site has rented and sold movies and TV shows from major studios since late 2008, most people watch videos on YouTube for free.

It's the first time YouTube is introducing all-you-can-watch channels that require a monthly fee. The least expensive of the channels at will cost 99 cents a month but the average price is around $2.99.

In the field of paid video content online, YouTube is playing catch up to services like Netflix, Hulu and Amazon, all of which have millions of paying customers.

But with a billion monthly visitors from around the globe, the Google-owned video service hopes to quickly add subscribers and add to the money it already makes from online advertising.

"This is just the beginning," said Malik Ducard, YouTube's director of content partnerships. The site plans to roll out a way for a broad number of partners to also launch pay channels on their own soon.

Corman, a producer and director whose influential cult classics like "Deathrace 2000" and "Piranha" earned him an honorary Oscar in 2009, said he's kept his 400-film library off of video streaming sites until now.

In an interview with The Associated Press, he said he turned down an offer from Hulu for about $5,000 to $6,000 per film several years ago, but sees promise in the YouTube offering. His channel, "Corman's Drive-in," will cost subscribers $3.99 per month for a rotating selection of 30 movies, refreshed with new interviews and clips from films that are in production. It is set to launch in June.

"I believed for many years that the future of motion picture distribution, particularly for the independents, is on the Internet," the 87-year-old said. "I think the time is now."

YouTube will keep slightly less than half of the revenue generated by the subscriptions.

Corman's wife and producing partner Julie Corman said they were taken aback at YouTube's potential after a clip of their 2010 movie "Sharktopus" went viral with 11 million views.

If even 1 percent of those viewers signed up for a subscription, it would amount to a healthy revenue stream, she said.

"The numbers are astonishing. We're waiting for the fireworks display," she said.

DHX Media Ltd., a Canadian company that owns the rights to 8,500 episodes of children's TV shows, is launching three paid YouTube channels, two for different age categories and one called "DHX Retro" that replays old programs such as "Inspector Gadget" and "Archie's Weird Mysteries."

It plans to launch in 10 countries and seven languages -- something that is much easier online than over traditional cable or satellite networks, according to DHX executive chairman Michael Hirsh.

"Clearing a channel across 10 countries would have taken a long time," Hirsh said. Doing it with YouTube takes just a "metaphorical flip of a switch."

As is the case with free videos on YouTube, the pay channels will be available for viewing on computers, mobile devices and Internet-connected TVs.

People who are accustomed to watching videos for free on YouTube are in for a slightly new experience. When viewers stumble upon a video requiring payment, they'll get a free preview up to 2 minutes long before being asked to subscribe.

Each channel comes with a 14-day free trial, but customers have to enter their credit card information through Google Wallet if they haven't already.

Several channels offer discounts on the monthly fee with an annual subscription, and some include features on top of access to videos.

Big Think, a New York-based maker of educational videos, will give subscribers who pay $2.99 a month access to videos of luminaries like Malcolm Gladwell, but also provide live question-and-answer sessions of an hour or more with experts.

Two new experts per month will be brought in to develop a series of 4-6 videos that are 2-3 minutes long. Each lesson is meant to distill advice that viewers can act upon immediately.

"This is e-learning for the YouTube audience," said Big Think president and co-founder Peter Hopkins. "We really had to take into account how to pack much more in and deliver on the promise of 'smarter, faster.' "