Nothing changed, and the only thing is I started using Google Adwords to promote from 9th Sep.

That could be the reason for the fall in clicks / CTR. But does anyone know Gs views nowadays on using both on the same site / pages?

because of google adwords? I'm penalized because that I'm starting to pay google...

If I got this right, then it's a thin line you are walking. You can't have Adsense on sites where Adwords campains land as a target, at least not landing pages. Careful with that, other than that, G uses some sort of magic to detect valid clicks but I get this as strictly related to incoming traffic from Adwords.

You can't have Adsense on sites where Adwords campains land as a target, at least not landing pages

That's my understanding too but I've always been a bit fuzzy on the sites vs pages matter (and this isn't the only subject where Google blurs that definition). I'm not an Adwords user so it doesn't really matter for me but I know I read somewhere that using Adwords to direct visitors directly to a page with Adsense on it is a no-no.

I've passed on free adwords budgets from Google due to the reason I monetize using adsense and don't want to risk running into arbitrage fallout down the line.

I've passed on free adwords budgets from Google due to the reason I monetize using adsense

Wow! I could have said this because that's been exactly my reasoning for years.

If you have a 'good' website, using Adwords shouldn't be a problem.
[support.google.com...]

You should first check your website for compliance with the Adsense ad placement policies. Do you have any social buttons or plugins that covers the ads when clicked/mouse over? Or do you perfectly align and color match ads with content which might confuse users?

There has been some talk that a new algorithm checks your website and determines if the click is valid or not.

the only thing is I started using Google Adwords to promote from 9th Sep.

I had been sending Bing traffic to a page with one Adsense bottom banner on it for years, with no problems. Suddenly, on August 31, the epc and ctr on that page tanked. Then the rpm for the entire site tanked by about 25%. So I took Adsense off that page, and the rpm came back up almost immediately. Now the rpm is higer than it was when I was running Bing to the site. I imagine that if that happened with Bing traffic, then they are doing the same to Adsense sites with Adwords traffic.

https://support.google.com/adwordspolicy/answer/190442?hl=en

That page contains what appears to be very clear advice on when Adsense / Adwords are / are not permitted together on the same site and even pages.

If I had faith in G I would maybe give Adwords a try but unfortunately I don't trust them to implement their own advice. It's also not clear where the advice is coming from - Adsense team? Adwords team? G itself? Too many times advice from one department of G has been contradicted by policy from another department.

To the OP, I would abandon Adwords on any Adsense site, give it a couple of months to settle down and see what happens.

thank you (ember, nomis5, explorador, levo), and I have disabled adwords compaign. meanwhile I sent an email to adsense support team to confirm what exactly happened. will come back later.
@nomis5, I read your link, and it says if you have good, unique, useful website, yes, your site will be allowed to use other traffic source.

The link above does provide some clarity but muddy waters persist because "useful" is a subjective term and Google continues to be the judge of that.

got reply from google, but not helpful. for it is a template reply, which just generally guide how to identify why CTR drop.

btw, I found the most of the penalized (clicks shaved) adsense publisher recovered in about two weeks time. don't know if it applies to everyone.

Did removing adsense solve the click shaving problem?

How long after you removed adsense did your ctr recover?

Same here. Since sept 19 my AdSense CTR (and earnings) have all but completely gone. It's quite devastating for me. I've done a lot of tweaking since then, but that didn't help.

Currently my CTR is down to a completely ridiculous 0.12%.

A large part of my income has simply vanished. And none of the alternatives I found are viable. I tried chitika, and that does give me a better clickrate, but the revenue per click is laughable: yesterday, for every 10.000 impression, I earned 4 cents! Really, people?

By the way: I did notice clicks and earnings appearing and disappearing; G is suddenly definitely shaving off many clicks off my account. Can't think why, I've always been very careful to follow the rules, even though G seems to change the rules in any way they please.

Very, very frustrating.

Still been shaving. I saw the clicks and earnings, then gone in several minutes. Nowhere to consult, ask their support team, only template email replied. WTF!

There may be hope. On July 1st my CTR dropped suddenly and dramatically and then on September 20 my CTR and CPC suddenly rose well above my July 1st levels. I'm keeping my fingers crossed that this will stick.

It seems like Google is testing different algorithms on certain publishers, maybe for a future update for all publishers.

My CTR has been going downhill now for months. They don't really have to shave anything, the payout has been so poor, I doubt I'll be able to even buy myself a new shaver.

Finally, my account recovered yesterday, hope it can stay.

Seems that it has nothing to do with Adwords or Bing ads, because I kept them active nearly all time, apart from several days testing.