What is an Attribution Model?
Attribution models determine the way you assign credit for online conversions to different touch points in a user’s journey. There are multiple ways a user can come to your site: through a direct entrance, organic search, paid search ads, emails, or web referrals. A single user may visit your site multiple times, coming from multiple sources before finally converting as a lead or a sale. Attribution models allow you to assign credit to the different clicks along that conversion path.
A Conversion Path Example
Consider Jim, who is in need of a new jean jacket. He googles “jean jacket” and clicks on a paid search ad for a jean jacket sale. Jim browses the site and sees a jacket that he likes, but he isn’t ready to pull the trigger yet. The next day, Jim wants to check out the jacket again. He googles the brand name and easily finds the site via another paid search ad. Indecisive as ever, Jim will visit the site two more times in the following two days before purchasing; visiting first through an organic search result, then by typing the URL directly into the address bar.
The sources in Jim’s conversion path are:
Google Paid Google Paid Google Organic Direct
As I go through the different Google Ads attribution models below, I will refer back to this example to determine which source would be responsible for the conversion.
Google Ads Attribution Models
Last Click - This attribution model gives all credit to the last clicked Google Ads ad and corresponding keyword in the conversion path. This is the default model in Google Ads and it is the most commonly used model.
- Jim’s jean jacket purchase would be attributed to the second paid search ad and corresponding brand keyword.
First Click - This attribution model gives all credit to the first clicked Google Ads ad and corresponding keyword in the conversion path.
- Jim’s jean jacket purchase would be attributed to the first paid search ad and corresponding “jean jacket” keyword.
Linear - This attribution model splits the conversion credit evenly across all Google Ads ad touchpoints in the conversion path.
- Jim’s jean jacket purchase would be attributed 50% to the first paid search ad and 50% to the second paid search ad.
Time Decay - This attribution model gives more credit to the touch points that happened closer in time to the conversion. The model uses a 7-day half life in which a click 8 days before a conversion gets half as much credit as a click 1 day before a conversion.
- With Jim’s jean jacket purchase, the first paid search click would get the least credit, while the second paid search ad click would get the most credit because it was the closest ad click to the conversion.
Position-Based - This attribution model gives 40% of conversion credit to the last clicked Google Ads ad, 40% to the first clicked Google Ads ad, and 20% split between all ad clicks in the middle of the conversion path.
- With Jim’s jean jacket purchase, there were only two paid search ad clicks, so the conversion credit is split evenly between these two clicks. However, had there been a third paid search ad touchpoint, the 1st and third ads would each get 40% of conversion credit while the 2nd ad would get the remaining 20%.
Data-Driven - This attribution model splits conversion credit using machine learning to determine the role each ad touchpoint played in the conversion process. This is the newest and most complex attribution model.
- With Jim’s jean jacket purchase, each ad touchpoint would receive a part of the credit, based on the role it was determined to play in the conversion path.
Differences Between Google Ads and Google Analytics Conversion Tracking
As an alternative to Google Ads conversion tracking, conversions can be tracked in Google Analytics and then sent to Google Ads through platform integration. The tracking setups are generally the same: you install a tracking code on every page of your website. However, conversion values will be different for tracking that is setup in Google Ads versus in Google Analytics for a variety of reasons, including differences in the attribution models.
Google Ads & Analytics Attribution Model Differences
By default, conversions are reported in Google Analytics using a Last Non-Direct Click attribution model. This is very similar to the Last Click attribution model used by Google Ads, except for one main thing:
- Google Ads looks at Google Paid ad interactions only, while Google Analytics looks at interactions from all sources.
To clarify this difference, consider the attribution of Jim’s Jean Jacket purchase on each platform:
- In Google Analytics: The purchase would be attributed to the Google Organic click, because it was the last non-direct click on the conversion path.
- In Google Ads (if using last click attribution): The purchase would be attributed to the last Google Paid ad click, because the attribution model only looks at Google Ads clicks.
This is an important distinction because under one model, paid search receives credit for the conversion while under the other, it does not.
After considering the differences between attribution in both platforms, you can decide for yourself which method holds the most value for your business. If you prefer to use Google Analytics tracking numbers, you can import your Google Analytics goals or transactions into your Google Ads account and bypass the conversion tracking altogether. If you decide to rely on Google Ads tracking for your paid search data, it would still be a good idea to setup Google Analytics tracking to see how conversions are divided across all sources and mediums.
Attribution Model Comparison
You can compare conversion data across different attribution models within Google Analytics or Google Ads, depending on where you have your tracking setup. This can be helpful in understanding your conversion paths, valuing your keywords, and picking the right conversion method for your account. View the differences in conversion metrics in available attribution reports in Ads and Analytics:
- Google Ads Attribution Model Comparison: Tools Attribution Attribution Modeling
- Google Analytics Attribution Model Comparison: Conversions Attribution Model Comparison Tool
Without proper tracking and attribution, it is impossible to get an accurate read on the effectiveness of your digital marketing. If your business could benefit from cleaner data, contact our team to find out how to get started.