Increase in warnings about ad code appearing on sites that you don’t own

We’ve spotted an increase in AdSense warnings about code appearing on sites that are not owned by the account.  The warning appears as a yellow alert bar on the home dashboard screen of AdSense, with the full text reading as follows:

In the past 7 days, your ad code has appeared a significant number of times on sites that you don’t own. To avoid lost revenue, make sure that you add these sites to your owned sites list in Site Management.

These warnings aren’t new, they have been a feature for some years. In the last month we have seen more than usual amount of warnings and we (sort of ) know why.

What does the warning mean?

When you generate and AdSense unit the code you are given is unique to your account.  Most AdSense users have their accounts configured to only count impressions from a specified list of sites. If a “significant” number of impressions appear from other sites this warning appears.  The purpose of the warning is to alert you if you have added your code to another site and forgotten to add it to your authorised sites list.

Why would my ad code appear on other sites?

There are four main reasons why your ad code is likely to appear on an unauthorised website:

1. You forgot to authorise a website
2. Someone is deliberately using your code
3. Someone is accidentally using your code
4. Your code has been scraped

To figure out which it is the easiest way is to run a performance report using the SITES criteria. This will show you which sites are showing impressions with your account code.  Compare this with the authorised/verified sites list to find the culprit. See this help item on managing verified sites.

It might seem like a good thing to have other sites running your ad code. After all, that means money for nothing!  We generally advise keeping tight control over the authorised/verified sites list though. As an AdSense publisher you are responsible for ensuring that your code is only ever displayed inline with policy.  If your code appears on a site that breaches policy then you will be held liable.

Why is this happening now?

We’re seeing Yandex.ru listed as a site in AdSense reports on almost every account that has just started seeing this problem.  Yandex is a Russian search engine. It would appear that something has changed in the way that they crawl sites which is causing the impressions to count.  Because they are quite aggressive at crawling, this is sometimes becoming significant enough to create the warning.

Do I need to be worried, and what can I do about it?

If you have site authorisation enabled (If you received this warning then you do) you do not need to worry about this.  You have already indicated to Google that this isn’t a site that you represent so will not be held accountable for anything that they do with the ad code.   If you don’t want Yandex crawling your site then you can also block it. Many webmasters comment that Yandex ignores robots.txt directives, but you can block the user agent to stop the crawling if you wish.