Understanding Google Analytics 4: Key Data Changes for Source Tracking
Published: 10/5/2023
Overview
This article addresses a vital analysis detail when using Google Analytics 4 (GA4). This change in how GA4 acts compared to the previous versions can risk marketers making decisions that could negatively impact their spend allocation.
GA4 Data Change
One of the most critical metrics marketers track is what specific sources are sending traffic to your website. GA4 has changed what data is displayed and how it is collected in the most common report marketers use.
“First User by Source” vs. “Session Source”
When logging into GA4, most people go to the “Acquisition -> Overview” page to review their traffic source numbers. However, that report and the “Acquisition -> User Acquisition” page default to the “First User by Source” field, not “Session Source”.
The “First User by Source” field, unless the individual tracking is a blogger or app owner, can be problematic as a primary analysis for most marketers. Per Google, “these are users who landed on your website or app for the first time through an organic search (e.g., through Google Search).”
The graphic above illustrates Sam’s two visits to an organization’s site and the source for each visit. Let’s walk through Sam’s visits to show how the GA4 report would capture the data:
- On the 1st of last month, Sam searched for the organization’s brand on Google and clicked the brand name on an ad. Sam went to the organization’s site and signed up for the newsletter.
- Imagine that the organization then sent Sam an email on the 26th of the month, which interested Sam and sent them back to the site, where they made a purchase.
- The GA4 default report, when reviewed, would show that Sam’s source is from Google’s paid ad, even though there was a delay between Sam’s visits of more than three weeks.