GA4 integrity

Executive Summary

Vampire Vape's GA4 property carries a trust score of 76/100, meaning a meaningful portion of reported data cannot be fully relied upon for strategic decisions. Two high-severity issues — a 147% spike in session_start events and a client-side event failing to reach GA4 — indicate likely tagging regressions or data loss that could be distorting traffic volumes and attribution. With £218,784 in tracked revenue and 6,939 purchases on record, resolving these integrity gaps is critical before using this data to inform budget allocation or funnel optimisation.

Key metrics

Ecommerce funnel

Top recommendations

1. CRITICAL — Investigate the session_start spike immediately: A 147% increase (41,442 → 102,220) almost certainly signals a duplicate tag firing, a GTM container change, or a theme/deploy update that introduced tag redundancy. Cross-reference your GTM change log and deploy history against the inflection date, verify via DebugView, and audit for duplicate GA4 configurations — inflated session counts will corrupt all per-session KPIs and paid media CPAs.
2. HIGH — Resolve the client-side event not reaching GA4: The view_item event on the Watermelon Nic Salt product page is firing in the browser but not being received by GA4, representing a confirmed data gap. In GTM Preview, confirm the /g/collect beacon is hitting the correct Measurement ID endpoint; if the tag appears healthy, check for GA4-side event filters or data stream misconfigurations. If the root cause is ad-blocker or CMP consent denial at scale, escalate a server-side GTM implementation as a medium-term fix.
3. HIGH — Audit the begin_checkout = 0 funnel anomaly: With 22,799 add-to-cart events and 6,939 purchases, zero begin_checkout events recorded is almost certainly a tracking omission rather than genuine user behaviour — this breaks funnel analysis entirely and masks checkout abandonment insights. Verify the begin_checkout trigger fires on your checkout initiation page in GTM Preview and ensure it is not gated behind a consent condition that most users decline.
4. MEDIUM — Validate and fix the zero page_view URL: The Watermelon Nic Salt product URL appears in your audit config with no recorded GA4 page_views, which combined with the client-side event gap suggests the GA4 tag may not be firing at all on this template. Load the page in GTM Preview to confirm tag status; if the tag is absent, check whether a recent template change excluded it from the container's trigger scope.
5. MEDIUM — Re-baseline all period-over-period reporting until tagging is stabilised: Until the session_start spike is diagnosed and corrected, any trend analysis comparing current vs. previous periods — including channel performance, conversion rates, and revenue attribution — should be treated as unreliable. Flag this to any stakeholders or agency partners using these reports to avoid flawed media spend decisions.
6. ONGOING — Implement a regular GA4 data integrity monitor: The combination of issues found here (event loss, duplicate firing, funnel gaps) suggests there is no proactive alerting in place for tagging anomalies. Configure GA4 Alerts or a third-party monitoring tool to flag >20% week-on-week changes in session_start, purchase, and key funnel events, ensuring regressions are caught within 24–48 hours of a deploy rather than retrospectively.

Findings

Trend vs previous period

Cross-reference with client-side audit