The world's most popular video site has confirmed it is considering the introduction of subscriptions for premium content.

According to a report that first appeared in AdAge, YouTube could start charging users up to $5 a month to access some of the site's most popular channels. 

Initially 25 premium channels would be introduced, as early as this spring, and the site is also considering charging for access to live events and content libraries. 

When asked by paidcontent if the reports were true, a YouTube spokesperson said: "We have long maintained that different content requires different types of payment models. The important thing is that, regardless of the model, our creators succeed on the platform. There are a lot of our content creators that think they would benefit from subscriptions, so we're looking at that."

Subscriptions could be key in attracting new channels to YouTube and in providing opportunities, other than through advertising, for content creators to earn money. Korean popstar Psy's "Gangnam Style" video earned $8 million from advertising, but the video, the most popular in YouTube's eight-year history, has been viewed 1 billion times. Therefore, it only earned .8 cents per view.