Are you using desktop, tablet or mobile?

I've found that it's only on one of my sites and it only happens on mobile

May be some kind of verification, to avoid accidental clicks.

In that case, it's likely to be connected to Google's ongoing actions to stop accidental clicks, which is prevalent on mobile.

See Google Addresses Accidental Mobile Clicks [webmasterworld.com]

I got hit on one site as well.
Its only mobile of course.

The strange thing that happened is that the CPC also dropped big time.

That's what I've heard but it only affects certain publishers. I've seen it before but then it's gone away. Has anyone ever experienced this before?

@Bensword When did it happen to your site?

@Grapetimes started on Feb 1st.

That's the same time it happened to me. This happened about a year ago as well and went away after some time. Is it on all of your mobile ads or just text ads?

On all ads. Can you check when it went away last year?

Maybe its like the arrows on desktop. When they wen missing for a week and came back.

I believe it was on my site for around 2 weeks. I don't think the ads will stay like that. What do you think?

Has anyone else ever dealt with this before?

it can also be an option advertisers can set , for not having to pay for accidental clicks. On mobile devices, this is so easy to click on an ad while scrolling, that it should happen all the time.

@Dimitri Has this happened to you before too and have you seen it before?

Anybody else with this problem?
I'm having this issue since February 1st and I have no answer from Google.

I wouldn't call it a "problem", but a "feature" against accidental clicks. Adsense might activate it depending of the data they are collecting for each account / page , and when they identify too many accidental clicks on mobile, they might activate this feature.

I'm with this problem since February 1st. On russian forums several webmasters have lost this "feature" and they don't know what actions help. Some says that remove adv on mobile phones, some says that did margins 30px. I hope for a quick recovery.

It depends how Google decided to use this "feature" or not. They might evaluate the position of the ad into the page, and elements surround to determine if there is risk of accidental clicks , or misleading positioning.

@Proenix: Google search "Sudden Drop of CTR 90% in 3 days" and you should find a thread on the Google forums about this, I can't seem to be able to post the link here. But I'll summarize it below:

From what I've read, it's an automatic feature that is triggered through an automated algorithm. As with most of Google's algorithms, we don't know the specifics of what triggers it. However, it seems evident that it's in place to reduce accidental mobile clicks. There seems to be a few things you can do to remedy the "problem".

1. Putting at least 20px space between content and ads
2. Labeling ads as "advertisements" or "sponsored links"
3. Making sure no ads are too close to navigation links or menus
4. Making sure no ads are above the fold

In other words, do everything you can to reduce accidental clicks. Obviously your CTR and revenue will decrease, but accidental clicks will also decrease and this "feature" will be automatically removed by the algorithm within 3 weeks (it usually takes less time than that).

>> 4. Making sure no ads are above the fold <<

I have one ad above the fold ( 320x100 ) on top of the pages, without problem. (it's alternatively a text/display ads or Ad Links).

Congratulate me! Through 2 month I have found solution of problem and now everything OK!

I have found solution of problem and now everything OK!

What did you do to fix the problem?

>> 4. Making sure no ads are above the fold <<

Every page I've created in the last 10 years has ads above the fold. Not one has ever had an issue.

Every page I've created in the last 10 years has ads above the fold. Not one has ever had an issue.

Careful. Displaying large ads ATF on mobile (300x250 and larger) is considered a violation.

Careful. Displaying large ads ATF on mobile (300x250 and larger) is considered a violation.

It's moved lower w/ responsive mobile for smaller screens..

I got this problem once again.
After couple of days of the blue visit site button I have realised this site had a warning from Google regarding ads below the fold.

I guess that in some cases this 300x250 ad I had was sometime showing (according to google) above the fold.

What I did was replace it with an auto responsive ad. This ad is automatically changes to 320x50 ad if it is automatically indicates it will show above the fold.

This solved the issue of the blue button in 3 hours.

Hi Bensword and welcome to WebmasterWorld [webmasterworld.com]

Good info. I was seeing that on a client's site (prior to my work.) He said he never received a warning from Adsense. Whether he did or not, now I know how to fix it.