YouTube says it’s going to start running its “TrueView” ads on some mobile devices. These are the “instream” ad units the video giant has been running on its main site since 2010, and they’re the ones that give viewers the ability to skip ads.

The things you need to know about this:

• YouTube gets a premium for these ads, since people have volunteered to watch them.

• For now, the only mobile devices where you’ll see the ads will be on Google’s Android devices.

• Google would love to show these ads on the iPhone, but it can’t, because the Apple-built YouTube app that’s on there now doesn’t have any ads at all.

• Which is yet another reason why Google isn’t complaining about Apple’s YouTube app going away, to be replaced by a Google-built one that will show ads.

Hypothetical contract renegotiation between Google and Apple regarding the built-in YouTube app:

_ Google : The licensing agreement that allows you to use the YouTube API without displaying ads is up for renewal. Will you modify the app to show ads now?_

_ Apple : No. Our users tell us they hate those ads._

_ Google : Ok, then we can’t give you an exemption to allow you to continue using the YouTube API._

_ Apple : So, we can’t include our version of the YouTube app in future versions of iOS?  You’re willing to forego the privileged _position of the app?

_ Google : Yes.  We’d prefer to build our own ad-enabled app and put it on the App Store._

_ Apple : Ok._