How we helped Castore to migrate 35+ sites to GA4
Castore needed to migrate 35+ international sites to GA4 and integrate many data sources. Fabric helped unify reporting, ensure accurate Shopify and GTM tracking, and build a centralised analytics platform, creating dozens of reports and enabling more consistent, reliable performance analysis.
GA4 Audit, GTM, BigQuery, Consent Mode, Data Visualisation
Shopify
The Challenge
When Google Analytics 4 (GA4) launched, Castore faced the complex challenge of migrating over 35 site domains from Universal Analytics. The business operates multiple international sites and subdomains across 7–8 regions, along with several B2B sites.
With each new partnership across football, motorsport, rugby, and basketball, Castore launches additional microsites for teamwear collections. Around 60–65% of their total sites are dedicated to these partnerships, each requiring its own analytics configuration and ongoing maintenance.
The task was not only to migrate all properties efficiently to GA4, but also to unify reporting, maintain data accuracyacross Shopify and Google Tag Manager (GTM), and create a centralised data warehouse capable of connecting marketing, sales, and financial insights.
The Strategy
Fabric began by conducting a full audit of all Castore websites before developing a custom data layer script to support the GA4 migration. Working closely with Castore’s in-house development team, we transitioned all Universal Analytics properties to GA4, ensuring complete data continuity across 35 sites.
In parallel, we took ownership of Google Tag Manager for all brand and partner sites and streamlined Shopify reporting, supporting both the eCommerce and marketing teams with daily analytics and maintenance. As platforms like Shopify, Google, and Microsoft frequently update their systems, Fabric continues to provide ongoing support to ensure consistent tracking accuracy and compliance across all properties.
To centralise reporting and enable deeper cross-channel insights, we scoped and built a marketing data warehouse in BigQuery, selecting Funnel as the ETL (Extract, Transform, Load) provider after identifying that the previous tool, Supermetrics, was not fit for purpose. The new infrastructure brings together data from 12 key marketing and eCommerce tools, integrating performance metrics, ROAS, and cost of goods sold into one unified environment.
With both online and in-store data collected through Shopify, Castore can now analyse performance and customer lifetime value (LTV) across every touchpoint. This shift from session-level to customer-level analytics enables the team to identify how customers move between channels — for example, whether professional teamwear buyers later convert into mainline retail customers.
The next phase of the partnership focuses on developing a master dashboard — a dynamic reporting tree surfacing key metrics with click-through capability into detailed dashboards for deeper exploration. Fabric continues to maintain and optimise all tracking setups, ensuring data accuracy across Facebook, Shopify, and Consent Mode integrations.
The Results
Fabric’s work delivered rapid and measurable impact across Castore’s global digital estate, including the implementation of Consent Mode across 30+ sites within just 24 hours, and the creation of 20+ reports as part of the new data warehouse project. With 145 different data sources integrated across 35 sites, Castore now benefits from unified GA4 and Shopify tracking across all brand domains and in-store sales—giving the business a single, connected view of performance.
Don't take our word for it, take theirs!
“Fabric combined GA4 best practice with a deep understanding of our unique setup.Their technical expertise gave our teams confidence in the data — and clarity across the business.They don’t just implement; they listen, adapt, and deliver.”
“We work with some of the biggest sports organisations in the world, so having absolute confidence in our data is critical. Fabric came in and delivered a full GA4 solution that met the standards we needed, while working closely with my team to make sure everything was done properly.
"Fabric have run multiple A/B and MVT tests across the site, uncovered some unexpected results, and been able to test bigger changes before committing to development. They also reviewed our site speed and recommended simple fixes — one of which reduced load time by 30%. Fabric have been brilliant at prioritisation, listening to what we need, and helping us move faster while making smarter decisions.”
