All businesses understand the importance of detailed, accurate data, and marketers are no different. We need reliable data to determine which campaigns are profitable, which to invest more ad spend into, which to scale and which to pause.

Notice how we stress “accurate” data. Accurate is the keyword here; the last thing that you want to do is end up optimizing your campaigns incorrectly based on poor information, limiting your own potential.

This is why marketing attribution models are so important. If you aren’t using the right attribution model for your business, you may not be getting a clear look at your actual conversion rates, skewing your data without even realizing it.

In this post, we’re going to discuss everything you need to know about Google Ads attribution models, making it easier for you to choose the right model for your campaigns.

What Are Google Ads Attribution Models and Why Do They Matter

Google Ads has several attribution models that you can choose from, which determine what ad campaigns get credit for a conversion. Some attribution models will only credit a single touchpoint, while others take the full customer journey into consideration.

Using the right attribution model will give you a better understanding of how successful your ads actually are at all stages of the funnel.

Here’s why this matters:

As much as businesses and marketers alike often wish this wasn’t the case, the average customer’s journey is typically complex.

Not all potential customers will see a single ad, think “that’s perfect,” click, and then convert on their first visit. Instead, they often need multiple interactions before making a decision.

For example, they might initially see your search ad, click thru to your landing page, and then click away to do more research. Then they’re hit with a remarketing ad that draws them back to your site, but they’re still not ready to convert, so they bounce again. Your last ad campaign is a retargeting ad that brings them back with a discount to incentivize purchase.

That’s a long, rambling paragraph because it’s a long, rambling journey. And with certain attribution models, all of that journey will be narrowed down to the point where only that last ad is given any credit for the conversion. This is true even though the user never would have converted on that ad if the user was never even pushed into (and nurtured through) the funnel without the other ads.

Different Attribution Models for Google Ads

There are eight different attribution models that you can choose from in Google Ads, each of which will credit conversions differently based on when the user interacted with the ad and at what point they converted.

Let’s take a look at each one and when it makes sense to use them.

Last Click

The last click attribution model (also commonly referred to as “last touch”) is the default model for Google Ads. It only credits the last ad that the user clicked within the attribution window for the conversion. This click gets 100% of the credit.

Though this is the default option, it’s important to keep in mind that it often fails to properly account for the entire funnel because it’s cutting out a major part of the picture. For many campaigns, the whole funnel matters and plays a role in conversion.

The biggest advantage with the last click model is that you will know without a doubt which ad ultimately generated the conversion, but that can still be tracked with other models.

First Click

The first click attribution model gives 100% of the credit to the first touchpoint the user interacts with. This is the touchpoint that introduces the user to your brand, service or product, and pushes them into the funnel.

The first interaction model can be useful in helping you assess which ads are most successful in driving quality traffic into your funnels that will ultimately lead to conversions. Once again, though, this model is relatively limiting because you have no idea what worked afterward.


Linear is one of the three attribution models that give some credit to all touchpoints in the funnel.

In this attribution model, all touchpoints are given equal credit, regardless of where they fell in the customer journey.

Attribution models that offer credit to all touchpoints can give a more accurate look at what’s working and what isn’t. The only disadvantage to a liner model is that all interactions are not always equally important in driving conversions. For example, you may not want a converting click from a brand keyword to carry as much weight as a click from a core keyword that brought the user into the funnel in the first place.

If you have a relatively short funnel where all touchpoints are of equal importance, this is a good option to consider.

Time Decay

In the time decay attribution model, all touchpoints are given some credit, with credit increasing with recency. The last touchpoint, therefore, would receive the most credit, and the second touchpoint would receive the second-highest amount, and so on.

One of the greatest advantages of this model is that it reflects that sometimes sales require momentum, with campaigns later in the funnel being even more crucial. The messaging has to be exactly right to get people to convert, and this model takes that into account.


Position-based models give attribution to all touchpoints, but they give the highest amounts of attribution to the first and last touchpoints. All other touchpoints have the remaining attribution divided equally amongst them.

The great thing about this multi-touch attribution model is that all points in the funnel matter and are credited, but the two most crucial touchpoints– the one pushing users into the funnel and the one that finally drives the conversion– are valued the most.

For businesses with longer customer journeys, this is a great model to consider. You’re able to cut out some of the noise and give the most attribution credit where it’s deserved.


The data-driven attribution model is an advanced option that uses more in-depth tracking to your ad campaigns based on user interaction. Credit is given to ads and keywords that are clicked, and that attribution is divided up based on how imperative Google judges them to be based on the conversion process.

There’s no easy formula here; Google’s algorithm carefully looks at a customer’s journey and the actual performance of specific ads when assessing which were most impactful.

The advantage here is clear; you can get more feedback about what ads are really mattering in your overall funnel, even if they’re somewhere in the middle where other attribution models may not account for them. This model does work just as well on both short and long ad funnels, so it’s versatile overall.

There’s only one downside to the data-driven attribution model: If your account isn’t driving enough traffic (which may be the case for a new account or one on a tight budget), you won’t be able to use this feature and you’ll need to use other attribution models in the meantime.

How to Choose the Attribution Model That’s Right for You

Most PPC platforms use the last-click model as their default option, including Google Ads.

Most businesses, however, will benefit more from using attribution models that take the full sales funnel into consideration. You want to have a strong overall picture of the full funnel to understand what’s working and what isn’t; this can even help you troubleshoot potential issues. As a result, using time-decay and position-based models can help you award the most attribution to high-converting parts of the funnel while still getting a big-picture view.

There are some cases where other attribution models may be advantageous.

First interaction attribution can be incredibly valuable for businesses like influencers or affiliate marketers. They want to get people to their page, following them, and start nurturing those relationships.

First interaction also shifts the priority towards looking at what keywords are driving users into the funnel early.

Last interaction attribution, on the other hand, can be a smart choice for business who are driving direct sales quickly. A business that sells $30 bouquets and sees a lot of immediate sales of direct searches, for example, could benefit from using that last interaction model. Users are unlikely to be doing a ton of research, so seeing which campaigns inspire them to act fast may be the most valuable data you can get.

Choosing an Attribution Window

When you’re looking at attribution, it isn’t just the actual attribution model that matters; your attribution windows matter, too.

Your attribution window determines how long after a user sees or interacts with an ad that said ad can be credited for a conversion (if it applies, of course, based on the actual attribution model).

Your standard conversion window on Google Ads is going to be 30 days (and a view-through of only one day), but you can customize this. Depending on your business, customizing this window may be a good way to go.

Some businesses will have customers that convert within days or weeks. Some, however, might have customers that need months.

If I’m looking up pearl earrings to wear to a wedding, for example, I’ll almost definitely make a buying choice within thirty days from starting my search. If, however, I decide to go on a two-week Alaskan cruise, it might take me months to research and make a decision.

It’s essential to choose an attribution window that reflects both your industry’s standard customer journey and your business’s typical customer journey, too. You can test this if needed. In general, look at how much time users spend on average researching before making a purchase, and extend the window just a few days beyond that.

How to Customize Your Google Ads Attribution Window

To customize your attribution window, head to the Settings part of Google Ads, and find “Conversions” under measurement.

Once there, you can customize your attribution window for each individual conversion action by editing the conversion itself.


Google Ads is a complex system, but all the customization options that make it so complex can be a direct benefit to your business. Not only can you set up incredible targeting to reach your target audience, but you can also choose how you want to track and attribute conversions so that you can properly optimize your campaigns moving forward.

Choosing the right attribution model for your campaigns is important. If you’re wondering where to start or what’s best for your particular campaigns, we can help! Get in touch here.