Analytics & Tracking: the truth layer behind every decision
Ecommerce analytics only earns its keep when GA4, Shopify/WooCommerce, ad platforms and email data agree on the same order. The stack that gets you there is GA4 enhanced ecommerce plus server-side tracking (CAPI + GTM Server) feeding one contribution-margin dashboard.
The average DTC brand runs four attribution truths Shopify, GA4, Meta, and Google that never quite match. Every quarter, someone loses an argument because of it. Fixing the tracking layer is the single biggest unlock for confident scaling decisions.
This hub covers a real ecommerce measurement stack: GA4 enhanced ecommerce, server-side tagging via GTM Server, Meta CAPI, Google Enhanced Conversions, plus the MMM + incrementality layer that keeps platform reporting honest.
Guides, playbooks and case studies
Enhanced ecommerce events, custom dimensions, exploration reports for PDP and PLP.
GTM Server on Cloud Run, first-party cookies, and cookie durability.
Event match quality (EMQ), dedupe, and profitable Advantage+ signals.
First-party data for smart bidding without breaking privacy rules.
Last-click, data-driven, MTA and MMM when each is right.
Robyn + Meta MMM Lift modelling incrementality without a data team.
Looker Studio and Sheets: contribution margin, MER, CAC/LTV in one view.
Consent Mode v2, CMPs, and GDPR-safe conversion signals.
The playbook, step by step
- 01Reconciliation audit
Compare Shopify orders vs GA4 vs Meta vs Google for the last 30 days. Anything above 5% variance triggers a fix.
- 02Server-side tagging
Deploy GTM Server (Cloud Run or Stape), migrate Meta CAPI and Google Ads conversions, and confirm EMQ ≥ 8/10.
- 03Consent + privacy
Consent Mode v2, IAB TCF-compatible CMP, and DPA sign-off on any new pixel or third-party script.
- 04One dashboard, one truth
Looker Studio dashboard blending Shopify (source of truth) with platform spend reporting MER, contribution margin, CAC/LTV.
- 05Incrementality layer
Quarterly geo-holdout or MMM refresh so platform ROAS never gets the final word.
Frequently asked questions
Do we still need GA4 if Shopify has analytics?
Yes. Shopify reports orders; GA4 reports behaviour (funnel, source, engaged sessions). You need both, and they should agree on orders within 5%.
Is server-side tracking worth the cost?
For any brand spending £20k+/month on paid, yes. Match rate improvements alone typically pay for GTM Server hosting in the first week.
How do we handle iOS signal loss?
Server-side events (CAPI, Google Enhanced Conversions), first-party cookies via GTM Server, and MMM as an honesty check against platform ROAS.
Which attribution model should we use?
Data-driven attribution inside platforms, contribution margin + MER for board-level decisions, and quarterly incrementality tests to keep both honest.