A comprehensive explanation of Google’s ad data exclusion feature

If you have a lot of experience advertising with Google Ads, you’ve probably come across a situation where Google Ads conversion tracking has issues, resulting in garbled conversion data for your ads. What do you do when this happens? How do you prevent garbled data from affecting your ad performance and data models? That’s where data exclusions come in. In this guide, we’ll explain what data exclusions are, why they’re critical to your advertising success, and how to implement them. What are data exclusions? Data exclusions are a feature in Google Ads that allows advertisers to exclude ad data for specific time periods. This feature is particularly useful if you’re experiencing a blackout (i.e., a period of time when your conversion tracking or Google tags aren’t working properly) or a garbled conversion data. Google Ads uses conversion data to optimize your advertising, especially when using smart bidding strategies like Target CPA (tCPA) or Target ROAS (tROAS), which rely on accurate conversion data to make bids that meet your advertising goals. When there’s a problem with conversion tracking in your Google Ads account, the smart bidding algorithm doesn’t know what’s going on and starts making incorrect bidding decisions, leading to inflated costs and reduced performance. The longer the problem persists, the more damage it will cause to your ad conversion performance. But data exclusion can mitigate the damage caused by the above situation. By proactively telling the Google Ads system to ignore the problematic data, advertisers can protect their ads from the impact of incorrect data in order to maintain the best performance of smart bidding. Why use data exclusion? Let’s say you are running a Google Ads campaign with excellent performance. Smart bidding strategies have been put into use for a long time, and the ad conversion results have always been able to meet the target cost per conversion (tCPA) or return on ad spend (ROAS) goals. But suddenly one day, the Google tag code stopped working properly for some reason, perhaps a code problem on the website, or a page update accidentally broke the tracking settings. Whatever the reason, the result is the same: there is a problem with the conversion data of the advertising account. Without this key conversion data, the smart bidding algorithm will be lost and will not know which clicks will lead to conversions and value, so it will start bidding unwisely, which will lead to soaring conversion costs, lower conversion rates, and poor return on ad spend. Even a short period of missing conversion data can have a lasting impact on advertising smart bidding. The longer it takes to resolve the problem, the deeper the impact of bad data on the learning of the advertising campaign. This is why the data exclusion function was created. By using data exclusion, advertisers can effectively “clear” bad data from the data memory of the campaign, thereby preventing the smart bidding algorithm from triggering bad data, which helps to maintain the accuracy and sustainability of advertising performance. Data Exclusion Example To help you really understand the data exclusion function, I will share a real example from my personal account. Problem Analysis The following Google Ads advertising account encountered some data problems in delivery: no conversions were recorded for a long time in the middle (blue line).

This was highly unusual as the account usually had steady conversion results every day. Investigation revealed an issue with the conversion tracking code on the site. Some pages had changed and the code was no longer firing correctly. This issue persisted for 6 days until it was resolved.

Before this, the cost per conversion was around $200, and when the problem was solved and the code started to work properly again, the cost per conversion suddenly soared to $500. What’s the reason? The smart bidding algorithm deviated from its normal track due to the lack of accurate conversion data. Solution Since we know exactly when the Google Tag code error occurred, creating data exclusions is the best way to mitigate the impact of abnormal conversion data. It’s best to expand the date range here to ensure that all bad data is filtered out 100%.

How to Create Data Exclusions in Google Ads (Google Old Account Demo) Now that we know the role and importance of data exclusions, let’s go over the process of setting up data exclusions in your Google Ads account.
Step 1: Identify the problematic time periodThe first step in using data exclusions is to identify the time period when the Google Tag code was having issues. You’ll need to carefully review your ad data to pinpoint exactly when the problem started and when it was resolved.
Step 2: Access the data exclusion featureOnce you’ve identified the time period that needs to be excluded, navigate to the Tools and Settings menu in your Google Ads account and select Bid strategies under Shared library.

Click Advanced Controls on the left side of the screen.

Here you will see two options: Seasonal Adjustment and Data Exclusion. In this article we will only cover data exclusion, so click on Data Exclusion.

Step 3: Create a new data exclusion In the Data Exclusions
tab, click the + button to start creating a new exclusion.

Give your data exclusion a name that clearly identifies the issue and date range, such as “Conversion tracking outage February 1-9,” to make it easier to find and manage the exclusion later.

Next, set the start and end time for the exclusion. In this example, I set the start time to February 1st and the end time to February 9th.
Step 4: Define the scope of your data exclusion
In this step, you will need to select the specific campaigns and devices you want to exclude. For example, if the tracking issue affects your entire advertising account, you will want to exclude all campaigns and devices. However, if the issue is limited to a specific campaign or device type, you can narrow the exclusion scope.

In the example above, I’m setting up my entire ad account, with all campaigns and devices selected.
Step 5: Save and confirm exclusions
Once set up, Google Ads will prompt you to confirm your settings. This is a critical step because data exclusion can significantly impact your ad’s performance. Before proceeding, double-check that your time range, campaign, and device settings are correct.

Once you’ve confirmed everything, click Save to create your new data exclusion. Google Ads will then apply the exclusion, effectively removing conversion data for the selected period from your advertising learning history.

What happens after implementing data exclusion
While excluding bad data can prevent long-term damage to your ad data, it doesn’t solve all problems instantly. After implementing data exclusion, the smart bidding algorithm will take some time to recalibrate, which may take about a week. During this period, conversion performance may fluctuate. Remember that the purpose of data exclusion is to protect the long-term performance of your ads, so please be patient and wait for the algorithm to return to normal.