The switch from Google’s Universal Analytics (UA) to the new Google Analytics 4 (GA4) has been full of surprises. It introduced numerous challenges, including inconsistencies and data gaps across various platforms. One major area of impact is Google Ads conversion tracking, where the implementation of new attribution models has led to unforeseen changes in data.
A recent case study by Bidnamic revealed substantial differences in conversion data when comparing the two platforms:
“GA4 was capturing around 15% fewer conversions compared to UA when Google Analytics is used as a conversion tracking method within Google Ads. When compared to Google Ads tracking, GA4 was tracking around 40% fewer conversions within Google Ads.”
These discrepancies in Google Ads conversion tracking data pose a significant challenge when making decisions for Paid advertisements. But before we can examine attribution differences between Google Ads and Google Analytics 4, it’s important to understand the terminology shifts between UA and GA4.
What Are Google Ads Attribution Models?
Understanding the source of website traffic is crucial for effective business decision-making. For instance, if you have 1000 users in a month to your site, you must know the traffic source for those users to make a key business decision.
Determining whether 1,000 monthly users arrived organically or through paid channels like Google Ads or Facebook Ads is a fundamental aspect of attribution.
That said, different platforms attribute in different ways, such as First Click or Last Click, to assign credit for conversions. However, the customer journey often involves multiple touchpoints (like social media, video ads, and search) before a purchase, making these simple models inadequate.
This is where “Data Driven Attribution” comes in, a kind of attribution that weights the different “touch points” in user journey.
But this brings up another issue: what are metrics?
What Is a User in Analytics?
Defining a “user” might seem straightforward, but not every platform identifies this in the same way. Some platforms count unique visitors who interact with a website, considering different devices as separate users. Others simply count visitors without differentiating based on device.
This chart from Search Engine Land illustrates these discrepancies:
Universal Analytics was the standard for many years, and its metric definitions became familiar to marketers. However, consistency across Google’s platforms has been a challenge, with discrepancies between UA, Google Ads, and other advertising platforms. Furthermore, Ga4 is trying to unify metrics from many different platforms: Google Ads, Microsft Ads, Facebook, TikTok, and others. This diversity in metric definitions across platforms complicates data analysis and comparison (you can read more about those differences here)
Google Ads Conversion Tracking Differences
While UA used cookies for more thorough tracking and measurement, Ga4 is dependent on the client side browser tracking. As more and more browsers move to a cookieless browsing experience, insert automatic privacy settings and ad blockers, this limits the abilities of analytics tools to effectively track and attribute the proper source. When the Ga4 cookie, pixel or tracking code is blocked Ga4 no longer has the ability to attribute the source. This causes the user to be marked as “Direct, Not Set,” or “Organic.”
For example, a user may come from a Google Ad, but depending on their browser settings, they can get marked as “Direct, Not Set or Organic.” The Bidnamics sourced above showed that Ga4 undercounted Google Ads conversions by 40%. In addition, various studies and pay per click forums report similar finding (which are in line with our own).
Google Ads Conversion Tracking Issues for Ecommerce and Booking Softwares
Booking softwares can also throw a wrinkle in things. Ecommerce forms and booking software often take the user offsite to complete the transaction (for good security reasons) and then bring them back to the site. But what happens is, if the cookies or tracking clears, Ga4 sees this as a new user, and often renders the purchase as “Direct” or “Not set.”
Google Ads Solutions For Data Attribution
While there is no clearcut, one size fits all solution, here are several workarounds for the data attribution.
1. Create Conversions Actions and Tracking in Each Platform Independently.
Google Ads, Facebook Ads, Ga4 each have ways of implementing tracking and conversion data. This creates a fail safe to find a better overal picture accounting for differences in attribution and tracking.
Solves discrepancies for phone calls and form submissions that happen on site.
Limitations: This may have a higher failure rate for bookings that go offisite and return if the tracking falls off.
2. Implement Offline Conversion Tracking and API
Most Ecommerce and Booking software can hold the tracking codes and send the source back to source platform. In this case a person clicks and ad, makes a purchase, and the software then sends the revenue amount and tracking back to the platform for more robust tracking.
Solves the issue of discrepancies in data for purchases that take users of site and then then return them. In this case even if the tracking falls off in real time, the purchase data records the source and sends it back to the originating platform.
Limitations: Not all ecommerce or booking softwares communicate with other platforms. So the booking software many only communicate with Ga4. In this case the source attribution would still be limited; though the totals will usually be right.
3. Old School Reporting Calculating Platform Data and Calculation Across Platforms
Helps get an overall marketing revenue look the issue of users and conversions being marked as “not set” or “direct,” by looking at the total clicks from the platforms themselves. If Google ads shows 100 users in a day, but Ga4 shows that only 60 came from Google Ads, you can bet many are showing up as “not set.”
If you have the total revenue values then attribute the value based on the percentage of users from a source. For instance if 15% of traffic is coming from Google Ads or Facebook, but Ga4 Revenue shows “Not Set”, you are better off attributing 15% of that value to Google Ads then assuming it’s all just mysteriously “not set.”
Limitations: It won’t be exact data points, because conversion rates often vary across platforms and sources. But it will get you a much better picture to what is happening.
In Conclusion
With the shift to Ga4 and the rise of cookieless browsing, there is not one tool that can be the absolute source of truth. Conversions and revenue need to be measured and calculated across various tools and then checked against their value’s received. One business may be able to get all their data from one platform, whereas another needs to use a complex combination of different tools and platforms to track the customer journey. The best thing is to work with your marketing and advertising specialist to implement custom strategies.