AdSense Referrers – How to spot the bad guys

In a recent Google+ thread several publishers were discussing unusual traffic patterns coming from a particular referring domain and expressing concern that these could be generating invalid clicks.

Understanding such risks is a vital part of the job of any AdSense publisher.  It is the publisher’s responsibility to spot and tackle unusual click activity. This blog post shows one quick and simple way to spot or rule out such problems.

Google Analytics – the only tool you need

This method simply uses Google Analytics, a tool that almost every AdSense publisher has available. The only requirement is that you have linked your Analytics and AdSense accounts, which hopefully every publisher does already.

(If not – do it! Once the accounts are linked you get access to a wealth of additional data anyway)

Spotting unusual or new traffic sources

The starting point for concerns over traffic sources is often the referrer reports in Google Analytics.  This can be found by navigation to Acquisition > All Referrals .

The referrals reports shows traffic that comes to your website from a link on another website. This traffic is grouped by domain.  This is a great report to keep an eye on for a number of reasons, but in this instance we are looking for domains that are new, unknown or suspicious.

In the report below I have obscured sensitive data, but have left a couple of interesting referrers in place that we might want to look at further.

What is it about these three that are of interest?

One is for an email service. That isn’t unusual in itself, but it you had a sudden spike in such traffic it might be something to take a look at.

The second is showing a reasonable number of visitors from an IP address, which is slightly unusual for many sites.

The final one is for a domain that is suddenly referring traffic that the owner might not be aware of.  I’ve used this example, as it was traffic being referred to Semalt.com that triggered the initial discussion.

Could any of this traffic be generating invalid clicks?

The biggest red flag for invalid clicks would be a high CTR for that traffic.  With your Analytics and AdSense accounts links it is simple to overlay AdSense performance data on to that report – just click the AdSense link above the traffic graph.

You can then just sort by AdSense CTR and you will see the sites sending the highest CTR traffic.

The problem with that approach is that low traffic referral sources that send one of two clicks can bury the really interesting ones.  I therefore like to add an advanced filter to show just those that will provide enough data to make the CTR a useful figure.

To do this first click the ‘advanced’ link above the data table:

We’ll then add a filter to show only those referrers with more than a specified number of visits. In this case I have specified a minimum of 1,000 . Any number over 100 works– you need to find the right balance for your site.  If 100 is too large for your traffic levels you can always specify a longer date range.

Now when you sort by AdSense CTR you get a much more accurate impression of which referrers are sending a high proportion of clicks.  In this case none of those top referrers are suspicious (they are all known to the publisher), but we have certainly identified some valuable traffic sources that we might want to cultivate!

This can be a useful report, both for spotting possible problems and for opportunities to build valuable traffic.  As such it might be worth adding it to your dashboard now for quick reference later – just click Add to dashboard back at the top of the page.

What about specific referrers?

Going back to the original online discussion, the question was whether one particular referrer, Semalt.com was sending invalid clicks. Checking that is even simpler. Clear the advanced filter and instead use the search box from the same report:

This allows us to quickly search for any referrer and see how many AdSense clicks they have generated. In this case 0. Phew!  Whatever they are doing, they are not clicking ads.

What happens when you do spot a “bad guy”?

Although everything checked out OK in the above example, problems do crop up. In one case we saw irregular spikes of high CTR traffic coming from a private areas of a forum. In that case it transpired that a competitor was encouraging others to “click bomb” the account and people were obliging by following the link that they posted.

If you do spot a problem the safest thing to do is to notify AdSense via the Invalid clicks contact form .  Using that form ensures that the details are on record.  I would tend to also include a brief summary of what further action you are taking.

You can also look at not displaying ad units to traffic originating from suspect domains. That is probably the topic of another blog post, but is reasonably easily achieved.