From the Fingers of Henrik Flensborg Rants, Raves and Recommendations about marketing and health

Opting out of Onsite Advertiser Sign-up isn’t enough…

...if you want to prevent Site Targeted Google AdSense ads from showing up on your sites.

If you opt in to "Onsite Advertiser Sign-up" then you'll see a link named "Advertise on this site" together with your Google AdSense ads.

All this does is send your visitors to a special landing page, and guide them to set up site targeting for your site specifically.

Now, I was under the impression that if I opted out of "Onsite Advertiser Sign-up", then I wouldn't get those Site Targeted Google AdSense CPM ads on my sites.

Well, I was wrong.

Initially I thought that I had accomplished my goal by opting out of "Onsite Advertiser Sign-up", but Site Targeted ads still showed up when I dug into some advanced reporting on my AdSense account.

Well, I was wrong.

So I raised a ticket with Google AdSense Support, and got a very fast reply that really described the Site targeting scenario,

Opting out of "Onsite Advertiser Sign-up" essentially just removes the "Advertise on this site" link.

And the email from the support team also stated that all Google AdSense accounts are opted in to Site Targeting per default.

Ouch, so basically Site targeting can't be disabled through your account settings.

I have one option though, but I have to wait for the support team to get back to me again before I know anything concrete.

The problem site targeting was originally brought to my attention by Adsense - Getting Paid Per Impression over at one of Lynn terry's blog.