Key takeaways
- The metric counts the purchase events sent, not the orders recorded in your system.
- A duplicate event inflates the figure: it's the most common and most discreet flaw.
- The transaction ID is the safeguard: without it, GA4 can't deduplicate.
Definition
E-commerce purchases count the occurrences of the purchase event received by GA4 over the period.
Worked example
A store sees 1,240 purchases in GA4 for 1,120 real orders. The 10% gap comes from a reloadable confirmation page: each customer who refreshes triggers a second event. Without a transaction ID, GA4 counts them twice.
Orders of magnitude
GA4 generally underestimates by 5 to 15% because of consent. An overestimate, by contrast, almost always reveals a technical duplicate.
The most common mistakes
- Not passing a transaction ID. It's what enables deduplication: without it, every reload counts.
- Counting purchases without looking at average order value. Volume alone says nothing about commercial health.
- Comparing to Google Ads conversions. The latter are attributed, these are measured: not the same object.
Where to find the metric
In GA4, the E-commerce purchases metric, in the monetization reports. First check in DebugView that the event fires once per order.
Frequently asked questions
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The Adwise team connects Google Ads, Meta Ads, LinkedIn Ads, GA4 and Search Console so agencies and freelancers can run their campaigns from a single place.