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  • Writer's pictureJoe Karasin

Google Ads Attribution Models

When it comes to conversions, understanding the journey a consumer takes is important for anyone running Google Ads. Attribution models are ways for advertisers to assign credit to various assets within the Google Ads platform.

Let’s use a real-life example. A consumer (we’ll call them Alex) searches for a new bicycle online. Alex finds an e-commerce store run by Leslie, from Leslie’s search network ad. Alex clicks around, looks at the brands and prices of the different bikes, but then leave the site without making a purchase. A week later, after visiting a local bike shop, Alex is back online and sees a display ad for Leslie’s bike store. Alex clicks the ad, and ends up seeing the perfect bike. Alex buys the bike, thus converting.

In a standard attribution model, Alex’s conversion would be attributed solely to the display ad, as the standard attribution model is last-click. But, shouldn’t the initial search ad get some of the credit? After all, if Alex had not clicked on Leslie’s search ad, she never would have been retargeted via the display campaign, and therefore, would not have discovered Leslie’s bike store online.

As you can see, to understand the performance of your ads, you might need a more nuanced attribution model for your ads when measuring conversions. Below, we’ll cover the 6 different attribution models available in Google Ads, and how each one would measure conversions.

The first attribution model is last click. Doing exactly what it says, this model attributes all conversions to the last clicked ad and related keyword. So in our example above, Leslie would see that the display ad was responsible for the conversion of Alex buying a bike.

Another important note is that Leslie would also see the keyword searched would be responsible for the conversion as well. In this situation, advertisers would want to know if any other searches were performed in order for the purchase to be made.

A first click attribution model would do the polar opposite, and assign all conversions to the search ad initially clicked by Alex and the corresponding keyword.

As you might think, this is not optimal when running complex ad campaigns with remarketing tools enabled, as you will not see the value in the subsequent ads that are key to creating conversions. Likewise, your keyword analysis would be thrown off by the attribution to the initial search.

More complex attribution models exist, which enable marketers and business owners to gain better insight into their efforts. Let’s explore those in more detail and see how they might be beneficial.

Linear attribution distributes all conversion credit equally. This means that if someone only clicks one ad, that ad will receive 100% of the credit, while if they click on 5 ads before converting, each would receive 20% of the credit. This is a more nuanced approach than first or last click attribution.

Linear attribution is ideal for testing, as each ad will get its share of credit for the conversion. In the example we started with, Leslie would see 50% of the conversion attributed to the search ad and 50% to the display ad. However, let’s say Leslie has 3 other ads active, and Alex did not interact with any of them. Then Leslie would see that those 3 ads did not perform and could be tweaked or even removed from the rotation.

Another Google Ads attribution model that is available is time decay. This model spreads credit across the ad journey, but gives more credit to the ad that was clicked closest to the conversion event. So, if Alex had clicked on Leslie’s display ad and made the purchase, it would get more credit than the search ad that Alex initially interacted with.

Bear in mind that this attribution model distributes the credit with a 7-day half life. So, if Alex had converted 8 days after the initial click, then that ad would lose 50% of its credit. If the conversion occurred within the 7 day window, then the full credit would still be applied.

Why is this important? Why use the time decay model? Understanding the purchase journey of your consumer will make you a more effective advertiser. If we see that there is a pattern of conversions occurring more than 7 days after the interaction, then increasing the frequency of our ads or adding new ads to the cycle might be appropriate.

Position based attribution might seem like it refers to ad position on the SERP, but it doesn’t. It actually refers to the position of the ad within the journey. So if Leslie were running 5 ads, and Alex interacted with the search ad first, and 2 other ads before the final interaction and conversion, then Leslie would see 40% attributed to the search ad, 40% to the display ad, and then 10% attributed to the two ads shown in between.

40% is the number assigned to the first and last interaction. The rest of the credit is distributed equally among the ads that the consumer interacts with between them. So if there were 10 ads, Leslie would see 40% to the search ad, 40% to the display ad, and then 2.5% assigned to the ads between them.

This is especially helpful in B2B marketing, where purchase journeys are often much longer than in e-commerce or other B2C marketing situations. Understanding what brought about an initial awareness and what drove the final decision is important, but each ad played a role and deserves credit.

Data driven attribution would be the most complicated, but possibly the most helpful model available. Data driven uses data from your account and distributes it among each interaction on the path. You’ll be able to see what keywords, ads, and ad groups are most beneficial in creating customers for your business.

Accounts must have sufficient data in order to select this attribution model. Generally speaking, you’ll need at least 15,000 clicks, and 600 conversion actions within a given 30-day period. So this model wouldn’t be optimal or even available for some small businesses.

Fortunately, you can use the other attribution models available to measure conversions and learn which ads are best serving your business goals. Want to drive conversions from Google Ads, but don’t know where to begin? Contact us for a no-obligation quote and learn how Karasin PPC can help you.

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