I just noticed this today. Can anyone clarify?
At the bottom of a thread page, I found the regular Google ads. There were also left- and right-scroll buttons, allowing me to move through about five “pages” of ads.
Is this new entirely, or perhaps is it just that now I see it as a member? {Thanks again, Rick.}
Or a third option, that I’ve just noticed it due to the lack of the other ads?
Please fight my ignorance.
Not only am I have a never seen that, at the moment, every page I check only has one ad at the bottom instead of three.
I only have one Google ad at the bottom of this page and no left and right scrolling buttons associated with the ad. There are “Previous thread” and “Next thread” buttons immediately below the ad. You’re not referring to them, are you? The previous thread and next thread do have different Google ads – that’s why I ask.
The only Google ad I have is for “Scrolling Displays” (like ABC Times Square Studios’) conjured up by the reference to scrolling in this thread.
Hold the phone. Immediately after posting my reply immediately above, the Google ads completely changed. Now I have four Google ads and left and right “scroll” buttons which bring up previous or next groups of three or four ads each – three backward and four forward.
Now I’ve got only one again:
I first noticed the scroll bars on the Google ads on my blog several weeks ago. I wasn’t notified about them then, either. They just appeared. I’ve since noticed them elsewhere.
I literally never notice the Google ads here. Even when I scroll down to the bottom of a page, my eye misses them. So I have no idea if they’ve been around the Dope for more than today.
These scrolling ads have been on Google Ads for at least a few months now.
My WAG: The Google ads are displayed according to some sort of logic – and for some threads they have a lot of stuff to pull from and for some they have only a few – or one, as I see on this page – it just depends on the keywords Google seizes on.
So you may have one ad or a lot of ads and if there’s more than 2 or 3 ads it scrolls the rest.
I wonder how many people are going to immediately check the site mentioned in your quote. I just did! 
Wow, those scroll buttons could have been there another 20 years and I never would have even noticed them.
I wonder if **this ** counts as ignorance fought 
Now I got an ad for scrolling LED displays.
I quick copied down the site in case the Google ad would disappear when I clicked Post Reply, as it then did in fact.
I wouldn’t have noticed them either if not for the OP.
Count me in as one who never noticed the scroll buttons either.
The scroll buttons themselves are unobtrusive – small, light blue, looking almost greyed-out – with plenty of whitespace, Google’s signature.
I’m not entirely sure I got an answer, but I appreciate the disourse.
Tuba, you may close this if you like.