A marketer once came to me with the classic question: “Why does GA4 show one number, CRM shows another, and Google Ads shows something completely different?”
Honestly? I wasn’t even surprised. Been there, stressed that. When I first switched from Universal Analytics to GA4, I’d stare at the reports thinking: “Is this a bug… or is it a feature?”
First, I blamed myself. Then the platform. Then myself again. Eventually, I started building a checklist of everything that could go wrong. Spoiler: it’s a long list.
The biggest pain in GA4? The data just doesn’t add up. What you see in the interface doesn’t always match:
• What’s sent to BigQuery
• What Google Ads is reporting
• And definitely not what your sales team sees
Why does this happen? The reasons range from annoyingly technical to downright philosophical:
1. Timing differences. GA4 logs by event time, Ads goes by click time. Cue confusion — especially at month-end.
2. Data modeling. If Consent Mode is on, some data is filled in with machine learning. Translation: what you see may be a beautiful guess, not a real user action.
3. Sampling Yep, GA4 still samples data in the UI — especially if you have large volumes or use fancy filters.
4. Different attribution models One report uses data-driven, another uses last-click, and a third is off on some session-based adventure. Everything matches… just not in this universe.
5. Bad event setup. Sometimes the same event fires twice — once from the site, once from GTM. Or maybe your event’s missing a key parameter altogether. Classic.
So what do I do when the numbers don’t match?
• I go to BigQuery. The only place where the raw events live. Sure, it needs some SQL, but it’s the closest thing to the truth.
• I check if Consent Mode is turned on — and how much of the report is modeled (fun fact: sometimes it’s half the whole thing).
• I fix my tracking. Making sure events fire once, have the right parameters, and triggers behave like they should.
GA4 isn’t your enemy. It’s just really good at saying: “Hey, maybe you don’t know your tracking as well as you thought.”
So if the numbers don’t line up, don’t panic — take it as an invitation to dig in and figure it out.
What to do next:
• Don’t blindly trust the first number you see in any report
• Learn to use BigQuery — it’s your analytics X-ray
• Set up your tracking so clean it impresses even you
• And most importantly: stop expecting all reports to magically align.
They won’t. They need to be stitched together — by hand, with brains and process.
If you work with GA4 to BigQuery exports, be sure to check out my SQL cheat sheet.
