The Google mobile interstitial penalty began rolling out this week. It seems to still be rolling out as we speak but some sites got hit pretty hard.

Glenn Gabe posted some examples of pages loosing ten or more spots in their mobile rankings because of their interstitial placements. He shared several examples of before and after rankings.

He also believes it is still rolling out because there are tons of examples he is tracking that have yet to be hurt by this. He told me:

Again, you can see the examples over here but many have been hit pretty hard by this update.

Although folks in a WebmasterWorld thread have not seen examples that hit them directly yet. But it is still early.

Forum discussion at WebmasterWorld.