Analytics
10 GA4 mistakes that lead you to wrong decisions
Date Published
GA4 honestly shows what you send it. The problem is what usually gets sent. Here are the ten mistakes I find most often in audits — each one distorts the data behind your budget decisions.
Setup mistakes
- Duplicate transactions: the purchase fires from the site, the server, and again on “thank you” page refresh. Reported revenue is 1.5× reality.
- No internal traffic filter: your team and contractors click conversions in.
- Referral exclusions not set: the payment gateway becomes the purchase “source”.
- No cross-domain between site and landing pages: one session becomes two.
- Default property time zone and currency: you compare days that never existed.
Interpretation mistakes
- Comparing GA4 sessions with Universal Analytics: different methodologies — the “traffic drop” is an illusion.
- Last-click attribution decisions on long sales cycles.
- Engagement rate mistaken for the old bounce rate.
- Privacy thresholds and sampling ignored: numbers “dance” and you blame the ads.
- Micro-conversions (scroll, phone click) mixed with macro (lead, purchase) — “plenty of conversions, no money”.
What to do
Run your analytics through a checklist quarterly: a test purchase, revenue reconciliation with the CRM, source check on the last 20 deals. One hour of work — and decisions rest on reality again. I can check your setup — it’s a quick audit.