Beyond last click attribution

Choose an attribution model that best fits your needs

There are numerous types of attribution models. You’ll want to choose a model that best fits your needs.

A brand new hotel with a big budget might value introducing people to their brand, while a trip planning software company cares about every ad interaction on the journey. It depends on what you want to get out of Google Ads. You’ll want to choose a model that best fits your needs.

Whenever you start the process of picking a new attribution model, remember to test how that model matches your overall approach to Google Ads. You want to see if it drives more value or more conversions and then decide if you’ve made the right choice.

Default to data-driven attribution

Choosing the right attribution model is a big decision, and it’s sometimes best to let the numbers do the talking. This is why data-driven attribution is the default attribution model for most conversions within Google Ads. A data-driven approach takes the guesswork out of choosing a model, and can help paint a clear picture of success in your account. Data-driven attribution learns from how your customers engage with your ads and subsequently convert to identify which ads are most valuable to your business. Moreover, as your account changes, a data-driven approach can evolve with it to continue crediting the touch points that are most impactful in driving positive business outcomes.

There are multiple benefits of using data-driven attribution:

  • Values all ad interactions on the conversion path
  • Works with automated bidding (as do the other attribution model options)
  • Works even on very short conversion paths
  • Quick and easy to implement

In most cases, data-driven represents the best way to accurately credit the most impactful campaign touchpoints in your account, allowing you to effectively optimize your Google campaigns. However, advertisers still have the option to use different attribution models.

If you’re looking for another option other than the data-driven attribution model, consider a rules-based model


If you use a manager account, use cross-account conversion tracking to combine your reported conversions. More data leads to better insights.

Like data-driven attribution, linear, time decay, and position-based models all break up one conversion across each ad interaction. Splitting up a single conversion across all ad interactions on the conversion path can give a clearer sense of an ad’s value. And all models let you take advantage of automated bidding as well.

  Model Description Growth strategy
Gives credit to ad interactions based on how imperative they were in the conversion process Based on account’s performance
Last click Gives all credit for the conversion to the last ad interaction Most conservative
First click Gives all credit for the conversion to the first ad interaction Most growth-oriented
Linear Distributes the credit for the conversion equally across all ad interactions on the path Moderate
Time decay Gives more credit to ad interactions that happened closer in time to the conversion Conservative
Position-based Gives 40% of credit to both the first and last ad interaction, with the remaining 20% spread out across the other ad interactions on the path Growth-oriented


The approach that you choose is going to determine the relationship between you, your Google Ads account, and your customer’s path to purchase. Attribution is about putting the performance of different keywords and ads into the proper perspective. Performance that seemed typical under pre-existing last click models could be very different when you evaluate those keywords and ads with a new model.

Keywords and ads earlier in the conversion path (often generic Search terms and creatives) usually behave differently than keywords and ads later in the click path (like brand terms and creatives). The following table shows how behavior for early vs. late influence keywords might differ.


Early influence keywords

Late influence keywords

Typical CPC



Typical CTR



Types of keywords

("things to do in Tuscany")

("Mom and Pop's Tuscan Tours")


A more aggressive model, like first click, will shift performance stats to reward ad interactions earlier in the conversion path, while a more conservative model, like last click, will reward ad interactions that occur later in the conversion path. As you decide what model to use, it might also make sense to re-evaluate the performance goals you have for your account. Many advertisers see better performance with lower cost per action (CPA) for ad interactions earlier in the click path once they move to an aggressive model, such as first click. If this is the case for you, consider increasing bids to get more volume at your previous CPA.

Here’s something to consider, especially in the days and weeks after you move away from a last click model: your costs will likely remain the same but your conversions may show a small, temporary drop. That's because the conversion lag for non-last click models tends to be higher than for last click models. This could make it seem, for a brief period of time, that performance is getting worse. Things should quickly stabilize as your account adjusts to new ways of counting conversions, but know that slight performance drops are expected after changing models.


When reviewing performance data, remember to choose an appropriate conversion window. If you update your conversion window, you may see additional conversions that originated from ad interactions that fall outside of your current date range. While your cost data will remain consistent (as it’s aligned with the date range you select), you may see more conversions appearing as you extend your conversion window.



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