AdSense Ad Serving Has Been Limited: What You Can Do

Ad serving limits have been a common pain point amongst AdSense publishers in recent months. Invalid traffic has been a major theme for Google throughout 2020 and there has been a rise in enforcement action in an attempt to protect the digital advertising ecosystem from fraud and bad ad experiences.

Seeing the warning that ad serving has been limited in your AdSense account is a worry and can be expensive. Through this guide, we’ll help you understand what to do if your AdSense ad serving has been limited and also how to prevent this from happening in the first place.

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What are ad serving limits?

Ad serving limits are account-level enforcements that restrict the number of ads that your AdSense account can show. Limited ad serving impacts publishers’ earnings directly because fewer ads are shown to users which means fewer clicks and less revenue.

Enforcement action is usually temporary lasting around 30 days but this can take longer in certain circumstances. There are usually two reasons why Google might place ad serving limits on an AdSense account, and the one that applies to you will be shown under “issues” alongside the account status notice:
Account being assessed: Google is monitoring your traffic profile in order to assess the quality of your website traffic and detect any invalid activity.
Invalid traffic concerns: Google has detected invalid traffic concerns that may be artificially inflating publishers’ earnings and advertisers’ costs.

The two issues are closely related with “Invalid Traffic concerns” being the more severe of the two. Both will result in a large proportion of AdSense / AdMob impressions being unfilled by Google, which can have a very severe impact on revenue.

Why does Google limit ad serving?

Ad Serving limits are used by Google to limit the impact of invalid traffic whilst they “investigate” a potential issue with some inventory. Similar to the dreaded Click-confirmation behavior (AKA the two-click penalty), it is a tactic that allows them to protect advertisers from an issue whilst determining whether there really is an issue to be concerned about. Whilst ad serving is limited, the AdSense tags will still be called, allowing Google to analyze every request. Fewer of those requests will result in filled impressions (ads on page), which means much lower revenue.

This seems to be an automated process. This “investigation” isn’t Google manually looking at your account performance, but simply your traffic getting greater attention from Google’s automated systems.

Limiting ad serving is just one of the tools that Google uses to combat Invalid Traffic on its network. Invalid Traffic (or IVT) is a catch-all term for traffic in the ad ecosystem that does not result from genuine human interest. It includes bots, accidental clicks, click-fraud, and incentivized traffic. Advertisers get no value from this traffic and reduce spend where it appears, so reducing IVT is in everyone’s long-term interest – even if the methods used can be very painful in the short term. You can learn more about identifying and preventing Invalid Traffic and Invalid Activity here.

Does limited ad serving affect AdSense and Ad Exchange?

At time of writing, we are only aware of ad serving being limited in this way with AdSense, not with Google’s premium monetisation solution Ad Exchange. This might be that the system has simply not been added to Ad Exchange yet, but it is equally likely that it will never be seen on Ad Exchange accounts. There are many many more AdSense accounts than there are accounts on the Google Ad Exchange. This means that AdSense tends to utilise more automated and machine learning systems so that they are able to provide support at the scale AdSense requires. Publishers with an Ad Exchange account are more likely to receive a call from their Google rep if there are traffic quality concerns, whereas AdSense relies more on automated processes for quality control.

What to do if your AdSense ads serving is limited

Once hit with limited ad serving, most publishers just wait for the limit to be lifted. Whatever a publisher does, they are going to have their ad serving limited until Google is satisfied that it has analysed enough data and is confident that there is not a problem. Frustratingly, this means that removing AdSense (to serve alternative ads for example) could mean the limit being in place longer whilst Google collects data.  For this reason, we don’t recommend removing the AdSense tags.

What publishers can do is maximise their chances of the testing being done resulting in a clean bill of health for their account. Whilst it can be difficult to diagnose issues when you can’t see ads being served, you can still go through your site and account addressing issues that could lead to invalid traffic:

• Check your traffic sources : Are you confident that you do not have significant traffic that is not from humans with a genuine interest in your  content? If not, then turn off of block any potentially problematic sources
• Check ad placements : Accidental clicks are a common source of invalid traffic. That that you have sufficient space between ads and other clickable elements on all common device types. Check that navigation doesn’t cover ads and that the placements aren’t going to encourage clicks (such as lining up with images or near next buttons). Consider whether the way you insert ads might be causing problem placements (this includes “Auto-ads” as well as ad insertion plugins). When in doubt, ad space.
• Check policy center : Many publishers don’t realise that invalid traffic can include ads served outside of what policy allows. AdSense policy centre can include plenty of clues to where Google has an issue with your ad serving. Work through the points flagged and fix them.

More details on these points can be found below where we discuss preventing limited ad serving.

Should I delete all my ad units and recreate them?

We have seen others sites advising that publishers delete all their AdSense ad units from account, remove code from page and recreate the units. These sites report that limited ad serving issue then fixes itself in a couple of weeks.

This isn’t a route that we are currently recommending. Where we have seen this approach used it  is not clear whether the issue was cleared because of the changes or would have been cleared in the same time anyway. Although it isn’t clear that it does work, it could theoretically work by interfering with Google’s internal reporting rather than either tackling the cause or allowing Google time to gain confidence in the placement. As such it would seem inadvisable anyway, as the limited ad serving issue would seem more likely to reoccur.

Someone has offered to fix the problem. Should I let them?

We are being made increasingly aware of publishers who discuss the option openly being approached by people claiming that they can fix it for them. These people generally promise quick results without convincing explanations of how they will fix the problem. As part of the process they will usually request access to sensitive systems like the AdSense account, Ad Manager, Search Console and/or website login or payment up front.

We would always urge extreme caution when sharing this access. Many scams that target publishers start with the same requests. Our advice would be not to share such access with individuals and companies that you don’t already have an established relationship with unless they have been vetted as part of the Google Certified Publisher Program (GCPP).

How can publishers prevent ad serving from being limited?

As publishers, it is our responsibility to ensure the quality of the traffic we send to our ad partners. This not only keeps our accounts in good standing but helps ensure strong bids and good long-term revenue. In practice, that can be difficult. Publishers don’t have the same visibility on traffic quality that partners like Google do. There are steps we can take prevent traffic quality issues though:

Play fair

The vast majority of publishers are not out to trick advertisers out of money, and those that are will be unlikely to read this guide. However, it can sometimes be difficult to make changes that have a short term cost impact. Publishers will often spot (for example) an ad unit that has an unexpectedly high CTR, and be slow to implement a fix that costs them money. This inaction can be costly if advertisers start reducing bids, ad serving gets limited or in the worst case accounts get suspended.

Being mindful of providing ad inventory that delivers value for publishers is a good way to promote long term success. After all, the highest-earning publishers didn’t get there by tricking their users into accidentally clicking ads.

Seek out strange patterns

Most AdSense publishers will be familiar with the CTR of their main ad units, but when did you last look at the relative click-through rate of a unit by Geo? Or Browser, or time of day? IVT isn’t always indicated by high CTR, but unusual CTR patterns can certainly be an indicator of an issue.

Periodically checking for these patterns can be a useful way if identifying issues early and seeing off problems before they occur. However, the same techniques can be crucial if you are trying to solve an issue with ad serving being limited.

The good news is that you already have the tools to do this. AdSense reporting provides incredible granularity and enables publishers to slice and dice the data in all sort of interesting ways.

This ad unit has an overall CTR of just 0.77%, but users in Norway are 45X more likely to click the same unit.

If you have your Google Analytics account linked to AdSense then you have even more options. Analyzing performance by device or traffic source can turn up equally interesting results. Be warned though – if someone was deliberately targeting your website with invalid traffic they may block the Analytics script from running.

Block bad traffic

If you identify bad traffic patterns then the best course of action is not to serve ads to that traffic. If you use an ad server, like Google Ad Manager, this can be done by adjusting your traffic. If you use “tags on page” (which most AdSense publishers do), then you can wrap those tags in some additional server logic to ensure that the page serves but ads do not serve to the suspect segments of your audience. A simpler approach is often just to block that traffic completely, either by adding some access rules to your htaccess file or using a firewall.

Consider a service like Cloudflare if you aren’t using it, and reconfigure it if you are

We’re big fans of Cloudflare here at OKO. Many publishers will already use Cloudflare in its primary role as a CDN / Optimisation service that speeds up their website for their users. Cloudflare is great for that, but it can also be a big help in the fight against invalid traffic.

Firewall rules: At the time of writing, firewall rules are only available in the Pro level of Cloudflare and above, but easily justify the $20/month subscription cost on their own. Using Firewall rules, you can easily put rules in place to block or challenge traffic that matches your suspect segments.

Bot fight mode: A less known, but excellent option is Cloudflare’s bot fight mode. This is a largely hands-off setting that is available even to domains on the free level of Cloudflare. Once enabled, Cloudflare will automatically look for signs of bot behavior and intercept that traffic. We’ve seen good results with this with information-rich sites that are often the targets of “unsophisticated invalid traffic” like scrapers.

Watch your ad spacing

One of the most common causes of accidental clicks is poor spacing between ad units and active elements, such as navigation and buttons. This is particularly a problem on mobile where the accuracy of a finger is so much poorer than a mouse pointer. Accidental clicks result in publishers paying for low-quality traffic as advertisers will reduce bids. Common examples of this are navigation that expands over ads and ad units close to buttons and navigation.

Don’t allow ads to be confused as content

Another common cause of accidental clicks is when ads are formatted to look like content. If users click an ad that they believe is content, they are very likely to click back or close when they end up on an unexpected site. This will be a clear sign of an unintended click to Google. This is another situation where publishers are sometimes reluctant to implement changes that reduce their short term revenue, but such issues can cause serious account level problems.

Be careful when buying traffic

There is a lot of confusion around AdSense and AdX and paid traffic, but it really is quite simple. There is nothing wrong with buying traffic for your site, but that traffic has to be genuine.
Genuine traffic doesn’t just mean human users either. Those users have to be visiting your site with genuine intent. Cheaper traffic will often come from users who are tricked into visiting (pop-unders, toolbars, redirects, etc) or incentivized to do so (pay to browse programs, etc). Both can be huge problems.

Other things to beware of are those companies who are effectively traffic resellers, buying their traffic from one site and selling it to another. Because there is a strong incentive for the originating source to send low-quality traffic, that will pass through the system and end up impacting your account. Content recommendation services can be prone to this. Even the best-known ones as they run vast networks and don’t have a great incentive to enforce traffic quality.

Traffic bought directly from top-tier sources like Google Ads, Facebook, and well-known content sites is generally safe, but it can be a good idea to introduce additional traffic quality systems if you are buying from other sources.

Can’t be bothered with all of this?

It’s no secret that ad serving has been getting more complicated in recent years. Invalid traffic is just the latest in a series of challenges publishers have had to deal with. With no end to the complexity in site, a growing number of publishers choose to partner with a Certified Publishing Partner like OKO. Working with OKO means partnering with an expert who can guide you through these complexities and even steer you away from them before they affect you. Get in touch today to find out how we can help you.