YouTube's subscription-based streaming music service, Music Key, launched in beta late last year. Five months later, its status hasn't changed. Perhaps the reason is because the Google-owned site has been focusing on bringing another subscription service to market - one that would eliminate ads on YouTube videos.

Popular content creators recently received an e-mail detailing the upcoming service. In it, YouTube said it will offer subscribers ad-free videos in addition to the ability to download content for offline viewing. The price is expected to be around $10 per month.

YouTube will be sharing a portion of the revenue it earns from subscriptions with content creators. Specifically, YouTube will set aside 55 percent of those earnings for content creators. From that pool of money, content creators will earn cuts based on their channel viewership.

The interesting bit is that, according to sources familiar with the matter as reported by The Verge, YouTube will require content creators to participate in the subscription offering. If they don't, all of their videos will be set to private. Ouch.

A specific date wasn't mentioned in the letter although the updated terms note the changes will go into effect on June 15, 2015. That doesn't necessarily mean the service will launch on that day, but it's worth mentioning anyhow.

The idea of a YouTube subscription service comes at a time of increased competition for the popular video sharing website. Facebook is quickly emerging as real contender and now that Vessel has exited beta, it could be a serious threat as well.