Sometimes the more information you have, the less you understand. Attribution is like that. There are a lot of nuances to attribution that can depend on settings at the account level, whether you are looking at conversions (aka key events) in Google Ads or Google Analytics and even by which dimension you have selected within your reports. Understanding these nuances is key to not misinterpreting what the data is telling you.
Default Attribution in Attribution Paths Report
Like Universal Analytics (UA), GA4 offers Attribution paths and models. These reports live under the Advertising tab. The very first report “Conversion Performance” relies on Google Ads conversions (which may or may not be GA4 key events, depending on what you use in Google Ads).
In the attribution paths reports, when you choose a primary channel, source, medium, source/medium it defaults to the attribution model set at the account level:
You have the option to change this and compare models in the Attribution models report – but the point is: know what you are looking at when you first open the report.
How Attribution Works in Reports
In the User Acquisition Report, you can choose a variety of dimensions, but they are all based off the “first user” meaning they are communicating how a user first came to your website. These dimensions are “user-scoped”.
Therefore, when you look at this report to see how well a channel or campaign is doing to drive a key event(s), you are looking at how that dimension (channel group, source, medium, etc.) contributed to the “first click” before conversion.
So, attribution in this report acts likes like a “first-click” model. There may have been many other touches that user had before converting, but the first_{dimension} is what gets the credit here.
In the Traffic Acquisition Report, dimensions are “session-scoped”. This report will tie key events to the source, medium, etc., that led to it within the session that the key event occurred. Therefore, the attribution in this report acts like “last click.”
Here is an example of the difference: This Session based Traffic acquisition report shows 25 and 13 “get a quote” key events for mediums “CPC” and “organic” respectively.
But in the User Acquisition Report, the one that has a “user-scope”, the story is a little different.
While CPC has the same number of key events attributed to it, organic does not, leading us to believe that organic brings in convertible traffic but they don’t convert necessarily in the same organic session. Whereas CPC brings in new people who tend to convert in the same session.
Choosing Dimensions in Explore Reports
Now on to the place where many of us spend our time trying to tease insights out of GA4 – the Explore Reports. In these reports you can choose whichever dimension scope you are most interested in. Keeping with the examples above, let’s focus on medium. We have the option to select medium, session medium, or first user medium. It’s here that you truly understand how Google frames the dimensions.
Medium sits under the heading “Attribution” and “session medium” and “first user medium” sit under the heading “Traffic Source.”
Plain “medium” will show attribution based on the attribution model you selected at the account level. For most of us, that would be the data-driven model. But if you aren’t looking for that model and instead want to see your data based on the medium that initiated the session or brought the user to the site in the first place, you can easily do that.
The Takeaway
Hopefully you now have a better idea what these types of dimensions are really telling you and when you go to build that Explore report, you’re more confident in which dimension to choose. Ultimately, which type of dimension you choose; user-based, session-based or model-based will depend on what type of question(s) you want to answer. It’s essential to be mindful with your selections in order to ensure you are accurately interpreting the results.
