joined:Sept 13, 2018
When you activate "anchor" ads ("Page Level Ads" ), this displays a sticky ads at the top or bottom of the screen, but only on mobile devices, and not to all users.
Today, at one of my site, I've seen this kind of anchor/sticky ads showing on desktop too, with a 728x90 banner.
So it's certainly only random experimentation, but the feature is certainly coming soon.
Of-course, it's sure that some will abuse of it, and ruin the idea. but personally, I like top / bottom sticky ads. On mobile, I removed all ads from my pages, and just let the anchor adsense ad. I find it more user friendly, and it earns more too :). If this feature comes to desktop, I am considering also removing all ad slots, and just keep this one.
Now ideally,I'd prefer to be able to show a 300x250 side column sticky ads instead of a 728x90 on top / bottom.
ps: it seems that these sticky ads (on desktop), are only showing if the viewport is 976 pixel wide or bellow.