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Project Summary
Following a competitive pitch in 2023, Performance Media agency, ROAST, was appointed by global B2B brand WEX. In April 2024, WEX’s U.S. division approached the WEX EMEA team with a strategic challenge: how could artificial intelligence (AI) be integrated into existing operations to enhance the current digital strategy, particularly in the realm of content creation?
Although ROAST already supported SEO and paid media activity, limited client-side resources hindered content execution. To solve this, ROAST developed a bespoke AI content solution using a custom large language model (LLM) that produced SEO-optimised, brand-aligned content at scale, all while human oversight ensured quality and governance. This initiative not only bridged an immediate resource gap, but also created a scalable, cost-effective content engine for the future. It positioned WEX EMEA as the pilot region for a broader AI strategy, reinforcing its status as a key innovation partner within WEX’s global business.

Strategy
WEX is a global commerce platform whose purpose is to simplify the business of running a business. The company works with companies in three areas, including fleet mobility, corporate payments, and employee benefits, to simplify complex transactions, manage expenses, and gain deeper insights through data. Through its rich data and specialised expertise in simplifying benefits, reimagining mobility, and processing payments, WEX has created a powerful ecosystem that offers seamlessly embedded, personalised solutions for its customers around the world.
The primary objective of the project was to integrate AI into the heart of WEX EMEA’s content production process in a way that improved efficiency, output, and quality, without compromising brand integrity or SEO performance.
More specifically, ROAST aimed to:
- Enhance operational efficiency by reducing the manual burden of content production, which had become a bottleneck.
- Enable scalable localisation of content across six key European markets: the UK, France, Germany, Belgium, the Netherlands, and Italy.
- Maintain strict brand consistency by training the AI to understand and replicate WEX’s tone of voice and stylistic guidelines.
- Safeguard quality through governance, ensuring all AI-generated content passed rigorous authenticity and compliance checks before publication.
- Demonstrate measurable business impact, particularly in terms of cost savings, time efficiency, organic search rankings, and increased traffic.
An additional objective was to support WEX’s broader innovation roadmap by acting as a pilot region for future global AI-driven marketing initiatives. This required not just a functional tool, but a thoroughly documented process, risk framework, and repeatable methodology that could be scaled or replicated elsewhere.

Execution
Execution of this AI initiative unfolded across three core workstreams, each critical to the project’s success:
1. Strategic Content Planning (SEO-Led Content Roadmap)
The first step was to lay a strong strategic foundation. ROAST’s SEO team conducted a comprehensive audit across five European markets, identifying priority topics, keyword opportunities, and content gaps aligned with business goals. This led to the creation of a pan-European content roadmap - rooted in search intent and localisation nuances - that would guide AI content production.
The strategy focused on three main pillars:
- Market-specific keyword research to identify local search behaviours.
- Content gap analysis based on current WEX domain authority and competitor content.
- On-site content structuring to maximise internal linking, topical authority, and SEO hygiene.
This roadmap provided clear direction for what types of content the AI would need to generate, and how that content would integrate into the broader SEO strategy.
2. Development of the Custom Large Language Model (LLM)
The second workstream involved building the custom LLM itself. Working with a specialist LLM developer and ROAST’s innovation team, the AI model was trained on a curated dataset including:
- WEX’s brand tone-of-voice documentation.
- Full content libraries from the WEX U.S. website (as EMEA content was limited).
- Internal SEO best practice documents.
- Keyword strategies, site architecture plans, and example content briefs.
This dataset enabled the LLM to learn how to write in WEX’s voice, incorporate SEO naturally, and structure content correctly. The training also focused on ensuring the AI could recommend relevant internal links by mapping existing site content.
A custom user interface was developed on top of the LLM to make it accessible to non-technical users, enabling content creators and strategists to input briefs, review output, and make edits easily.
Training was iterative. Over several weeks, SEO-informed content briefs were run through the model, and results were reviewed, edited, and re-fed into the system. This human-in-the-loop process significantly improved the model’s accuracy and output quality.
3. AI Content Authentication and Governance
To address the critical need for compliance and quality assurance, the third workstream focused on AI-authenticated content evaluation. Using the Winston API - an AI detection and scoring tool, each piece of content was benchmarked against a “human-likeness” score out of 100. After scraping over 200 high-ranking Google results, a threshold of 70/100 was established as the acceptable benchmark for publishable content.
This tool was integrated directly into the content creation process, flagging any AI-generated paragraphs with low scores. These sections were manually reviewed and tweaked to meet the threshold, adding another layer of human oversight.
Concurrently, the team developed a risk assessment framework with WEX to identify potential content governance issues, define escalation procedures, and create a full audit trail - essential for a regulated, enterprise-level business.

Effectiveness
Since launching the tool in November 2024, the project has delivered outstanding results across multiple metrics:
Performance and Organic Growth
- Over 550 new keyword rankings achieved across priority markets.
- 300+ of those keywords are now on page one of Google search results.
- WEX content now appears in AI-generated search experiences, including ChatGPT, Perplexity, and Google’s AI Overviews.
- Comparing the periods pre vs. post-launch, WEX has seen a +393% increase in non-brand organic clicks.
Comparing July-November 2024 vs. December 2024-April 2025

Content Production Efficiencies
- The AI tool can create 10+ articles per month, each aligned with SEO strategy and brand tone.
- Average time to first draft content dropped to under 20 seconds.
- Human editing and reviewing time greatly reduced, thanks to quality-first model training.
- New "social media post generator" tool allows for instant generation of LinkedIn, Meta, and X posts, enhancing multi-channel activation.

Scalability and Localisation
- The LLM features multi-language capabilities, enabling the generation of fully localised content in five languages with minimal manual input.
- Internal teams can quickly generate content briefs and publish-ready drafts, freeing up resources for strategic planning.

In conclusion…
This AI initiative exemplifies how automation and human governance can coexist to drive real business value. By thoughtfully integrating AI into the content workflow - with rigorous controls, deep training, and clear strategic alignment - ROAST helped WEX transform a complex, resource-intensive task into a streamlined, high-performing engine of growth.
The collaboration not only unlocked efficiency and savings but also delivered measurable uplifts in organic visibility and digital performance. WEX now has a scalable, future-proof content solution that aligns with global innovation goals - and serves as a benchmark for AI-driven marketing transformation across the organisation.
ROAST helped enhance WEX’s content strategy and deliver breakthrough results.

Client Testimonial
“ROAST's expertise has been invaluable in helping WEX navigate the complex digital marketing landscape across EMEA. We’ve been consistently impressed by the performance of ROAST and the incorporation of the AI Content Engine — a scalable content solution that has not only delivered outstanding results but also supported our global innovation ambitions.”
Joren Herremans, WEX, EMEA Revenue Marketing Director