Unless you do numbers like Ray William Johnson above, you probably won't be monetizing your YouTube videos on mobile devices any time soon. 

To help content makers monetize their mobile traffic as effectively as on computers, YouTube this week launched the TrueView In Stream video ads on mobile devices. The TrueView in-stream ad are essential pre-rolls, ads that you see at the beginning of the video, before the main content.

According to YouTube, you don't need to make any changes to your channel to take advantage of TrueView on mobile. If you opted to show TrueView ads on your on videos, this will now include traffic  from mobile devices.