Why tracking breaks (even when you do everything right)
- Platforms optimize on their own click/view attribution; GA4 often reports last-click or data-driven attribution.
- Cross-device and iOS privacy limits create gaps; the absence of clicks in analytics does not mean ads didn't influence.
- Naming inconsistencies (source/medium/campaign) quietly destroy trend analysis.
A UTM standard that scales
- Always tag: utm_source, utm_medium, utm_campaign; optionally utm_content/utm_term for creative/keyword.
- Keep a controlled vocabulary (e.g., source=facebook/google/tiktok; medium=cpc/paid-social/email).
- Use a campaign naming convention that encodes intent and geography (e.g., nb-search-us-brand).
GA4: what to check first
- Confirm conversion events fire once (dedupe between pixel + server events when applicable).
- Verify source/medium and default channel groupings match your expectations (sample paid traffic daily).
- Use consistent lookback windows when comparing GA4 to platform dashboards.
How to interpret conflicting numbers
- Use platforms for optimization and GA4 for directionality; reconcile with MER and incrementality tests.
- Expect GA4 to undercount in privacy-heavy environments; use it for relative comparisons, not absolute truth.
- If branded search spikes with spend, treat it as influenced revenue rather than 'free' traffic.