Retail GA4 tracking or “Google Shopping App
Purchase” – What is the Difference?Hello! I work for a digital advertising agency and we just got a new retail client with an existing Google Ads account. They currently have two conversion purchase actions set up and both set to primary – one is GA4 which tracks purchases made on the website, and one is called “Google Shopping App
Purchase.” After doing some research it seems like the “Google Shopping AppPurchase” is automatically added by Shopify.
I have a couple of questions if someone can please help: What is the difference between them? Are they tracking the same thing and we’re double counting (their numbers are usually pretty similar from day to day)? Does the “Google Shopping AppPurchase” only track purchases made through Shopping Ads/Shopping (we also see these conversions coming through across our search campaigns so we’re unsure). Which one (or both) should we use as “primary” conversions?
Thanks!!
The short answer is:
Yes, your two primary purchase conversion actions, the imported Google Analytics 4 purchase event and the “Google Shopping App Purchase” action from the Shopify Google & YouTube App, are almost certainly tracking the same transactions and leading to a significant double-counting issue in your Google Ads reporting and bidding.
The primary difference is the source: the GA4 conversion is imported from Google Analytics, which uses its own attribution model and measurement method, while the “Google Shopping App Purchase” is a Google Ads conversion action created directly by the Shopify app’s integration.
To resolve the duplication, you must choose one as your Primary conversion action for bidding and optimization, and set the other to Secondary (or remove it), thus using the Google Ads API to manage and synchronize your conversion settings and to ensure only the selected Primary action is fed into automated bidding strategies.
The “Google Shopping App Purchase” action tracks all purchases regardless of which campaign type drove the click, including Search and Shopping.
The long answer is:
The core of your problem is a common configuration error where two distinct tracking methods, both recording a purchase event, are feeding into Google Ads and are both set to “Primary,” resulting in conversion and conversion value inflation, which misleads your optimization algorithms and reporting.
The “Google Shopping App Purchase” action is a proprietary Google Ads conversion that the official Shopify API integration, via the Google & YouTube app, automatically creates and injects directly into your Google Ads account using a form of the Google Ads API for conversion management and its own tracking tag, sometimes referred to as ‘Trekkie’ tracking on the Shopify platform.
This action is designed to track all purchases on your Shopify store that can be attributed to a Google Ads click, and crucially, it is not limited to Shopping Ads but will credit purchases from all campaign types, including Search, which explains why you see those conversions across your non-Shopping campaigns.
The other action, the GA4 purchase conversion, is a transaction event recorded by Google Analytics 4 on the website and then imported into Google Ads through the property linking, a process that relies on the Google Analytics Data API and the Google Ads API to sync data.
Because both systems are measuring the same user action – a completed purchase – they are reporting it as two separate conversions in your Google Ads’ “Conversions” column when both are set to Primary.
The fact that the numbers are similar day-to-day strongly confirms this duplication.
To fix this, you must set one of the conversion actions to Primary and the other to Secondary under the ‘Goal and action optimization’ settings in Google Ads.
Best practice for an ecommerce business running Google Ads campaigns is typically to use the Google Ads-native tracking (the “Google Shopping App Purchase” in this case) as the Primary conversion for bidding, as it is generally quicker to process and provides data-driven attribution models that are often more optimized for ad campaign performance, while setting the GA4 import as Secondary for comparison and a holistic view.
Alternatively, if you want a cleaner, server-side method for all purchase data, you could consider leveraging the Shopify API to send purchase data to a Server-Side GTM container running on Stape or GCP, and then use the Google Analytics Measurement Protocol to send a single, authoritative purchase event to GA4, which in turn is imported into Google Ads.
This more complex server-side implementation ensures superior data quality, higher conversion rates due to resistance to client-side issues, and is a future-proof, cost-effective method of data synchronization over relying on potentially conflicting client-side tags and app integrations.
If you only use one method as Primary, your bidding will be optimized correctly, solving your double-counting problem.
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