YouTube is introducing a subscription service, with children's programmes like Sesame Street, films and some sport programmes all becoming part of the paid service.
Earlier this year, Psy's Gentleman video became the most viewed YouTube video over any 24-hour period - crucially because it is free to view.
YouTube already offers the option to buy films online, but this is the first time that whole video channels have been subject to a paid subscription - most of YouTube's content is still free.
The service will be available in 10 countries, and prices will start at 99 cents (64p) a month, with the average being $2.99 (£1.94.)
Also among the 51 channels are Ultimate Fighting Championship Plus, TNA Impact Wrestling Select, and National Geographic Kids.
Malik Ducard, director of content partnerships at YouTube, said the "this is just the beginning".
He also added that YouTube had “always been about unleashing the world’s creativity...This is an important next step in that journey”.
Acorn TV, which offers streaming of several British television shows, has signed up, offering Midsomer Murders, Pie in the Sky and others for $4.99 a month.
Producer and director Roger Corman told the Associated Press that he had previously turned down offers from video sites such as Hulu in the past, but is optimistic about YouTube's plans.
He is set to offer a selection of 30 films on his channel, as well as new interviews and production clips, for a cost of $3.99 (£2.59) per month.
"I believed for many years that the future of motion picture distribution, particularly for the independents, is on the Internet," he said.