The Verge writes code found in a YouTube app update hints that the service will soon release channels that run on a paid access model:
According to Android Police, the latest Android version of YouTube includes the following lines:
You can only subscribe to this paid channel on your computer.
You can only unsubscribe from this paid channel on your computer.
We haven't yet been able to confirm for ourselves, but the messages seem fairly straightforward, backing up the reports that we heard in January. At that point, AdAge sources said that YouTube planned to launch channels that would cost between $1 and $5 a month to subscribe to, with the option to include ads.