South Western Railway Case Study
15%+ ROAS uplift with CDP and tag management optimisation
Dexata partnered with South Western Rail to audit and rebuild their Customer Data Platform, helping them achieve a 15%+ increase in ROAS and 138%+ increase in paid media impressions.
Industry
Transport
Location
London – UK
Solutions
CDP Optimisation, Identity Resolution, Tag Management, Server-side CAPI
Results
138%+ Impressions, 15%+ ROAS
BACKGROUND
A strong platform,
not fully wired
South Western Rail engaged Dexata to support them in auditing their data estate, making and implementing recommendations to enable them to build a strong, future-proof data foundation.
South Western Rail’s customer data platform had disjointed data pipelines, and they were not using their platform to its full capabilities resulting in reduced ROI from paid media and an incomplete view of the customer journey.
The opportunity wasn’t a platform replacement. It was an architecture fix: cleaner identity resolution, consistent data layers, and server-side signal passing to restore the accuracy their ad platforms depended on.
SOLUTIONS DELIVERED
MarTech Architecture review and rebuild
CDP Optimisation across web and app
Identity Resolution for unified profiles
Server-side CAPI across paid media channels
Tag Management governance and cleanup
Training and Enablement for internal teams
COMMERCIAL IMPACT
Numbers that move the board
Since Dexata implemented the recommended optimisations to South Western Rail’s Customer Data Platform and Tag Management Platform, the commercial uplift has been considerable.
15%+
ROAS Increase
138%
Impressions Increase
70%
Lookalike Conversion Uplift
Words From The Client
HOW WE DID IT
Three workstreams,
one coherent fix
Dexata optimised South Western Railway’s CDP and Tag Management setup through three coordinated workstreams, each reinforcing the next.
Identity Resolution
Unified customer profiles across web and app, stitching fragmented touchpoints into a single coherent view of the passenger journey and enabling richer audience segments.
Server-side CAPI
Implementing Conversions API across all paid media channels — bypassing browser-side signal loss and restoring the data accuracy that ad platform algorithms depend on to optimise spend.
Web & App Data Layers
Redesigning data collection architecture from the ground up — standardised event schemas, consistent naming conventions, and reliable pipelines into the CDP and downstream channels.
Let's unify your customer data and scale ROI across markets
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