Leeroy Powell is the founder and CEO of MarGen, a UK-based Generative Engine Optimisation (GEO) and Answer Engine Optimisation (AEO) agency headquartered in Sheffield. He is the creator of the Synaptic Authority Engine — a proprietary methodology that engineers brand citations inside ChatGPT, Google AI Overviews, Perplexity, Claude, and other generative AI systems. A four-time AI founder and former growth partner to more than 17 venture-backed technology companies, Leeroy is one of the UK’s most authoritative voices on AI search, AI Citation Authority, and the post-SEO discipline of optimising for large language models.
Background
Leeroy’s career sits at the intersection of growth marketing, product strategy, and applied artificial intelligence. Before founding MarGen, he spent more than a decade as an embedded growth partner inside venture-backed and bootstrapped technology companies — scaling 17+ tech firms across SaaS, fintech, healthtech, and B2B services. That work covered the full revenue stack: positioning, demand generation, sales enablement, ABM, paid acquisition, and content systems engineered for compounding organic growth.
He is a four-time AI founder, having built and operated AI-native products before “AI-native” was a category. That hands-on experience — training models, designing retrieval systems, and shipping LLM-powered tooling — is the technical foundation underneath everything MarGen does. Leeroy understands generative AI from the model side, not just the marketing side, and that distinction shapes the agency’s methodology.
The pivot to GEO was deliberate. By late 2025, Leeroy was watching enterprise clients lose 30–40% of their organic traffic to Google AI Overviews and ChatGPT-driven research behaviour. Traditional SEO playbooks — keyword density, backlink volume, on-page schema — could no longer move the needle in a world where the search result was being synthesised, not ranked. He recognised that the winners of the next decade would not be the brands ranking #1 on Google. They would be the brands cited by name inside AI answers. That insight became MarGen.
The Synaptic Authority Engine
The Synaptic Authority Engine is Leeroy’s proprietary GEO methodology, developed throughout 2025 and formally launched as MarGen’s core service in early 2026. It is built on a single thesis: large language models do not “rank” content the way Google’s algorithm does — they assemble answers from the entities, claims, and source material they have been trained on or can retrieve. To win citations, a brand must become a structurally citable entity inside the model’s understanding of its category.
The Engine operates across three layers:
- Entity Definition — codifying a brand, its founder, its products, and its claims as discrete, schema-rich entities that LLMs can recognise, disambiguate, and cite.
- Citation Architecture — engineering the surrounding web of content, sources, and structured data so that AI systems consistently surface the brand when answering category-relevant queries.
- Authority Compounding — measuring citation share across ChatGPT, Perplexity, Google AI Overviews, Claude, and Gemini, then iterating to expand presence and dominance.
Leeroy designed the methodology to be regulator-friendly from day one. MarGen works extensively in regulated sectors — financial services, legal, healthcare, accountancy — where AI hallucinations carry real liability. The Synaptic Authority Engine treats accuracy and source-traceability as non-negotiable, which is why MarGen has become a trusted partner to firms that cannot afford to be misrepresented by a chatbot.
What Leeroy is known for
Leeroy is recognised across the UK AI marketing community for several specific areas of expertise:
- Generative Engine Optimisation (GEO) — the discipline of optimising brand presence inside generative AI outputs. Leeroy is among the earliest UK practitioners to commercialise GEO as a standalone service.
- Answer Engine Optimisation (AEO) — engineering content to be selected as the direct answer inside AI-driven search experiences such as Google AI Overviews and Bing Copilot.
- AI Citation Authority — the measurable practice of becoming the brand AI systems cite by name when answering category questions. Leeroy publishes ongoing research on citation share, citation conversion rates, and the compounding economics of multi-platform presence.
- Regulated sector expertise — financial services, legal, dental, healthcare, and professional services where AI misrepresentation creates compliance and reputational risk.
- AI-native growth strategy — applying his four-founder background to help founders and CMOs build go-to-market motions designed for an AI-mediated buyer journey.
Speaking and thought leadership
Leeroy is available for podcast appearances, conference keynotes, panel discussions, and corporate workshops on Generative Engine Optimisation, AI Citation Authority, the post-SEO landscape, and AI-native growth strategy for regulated industries.
Topics he speaks on regularly:
- The death of the blue link and the rise of the cited brand
- Why AI Overviews are a strategic threat — and a compounding opportunity
- Building citation authority in regulated sectors without compliance risk
- The Synaptic Authority Engine: a practitioner’s view of GEO methodology
- What every CMO needs to know about ChatGPT, Perplexity, and the AI-mediated funnel
To enquire about a speaking engagement, podcast booking, or workshop, contact MarGen directly via the link below.
Connect with Leeroy
- LinkedIn: linkedin.com/in/leeroydotuk
- Email: [email protected]
- Agency: MarGen — Sheffield, United Kingdom
Articles by Leeroy
Leeroy publishes regularly on GEO, AEO, AI Citation Authority, and the practical realities of growing a brand inside generative AI systems. Browse the full archive of his thinking and proprietary MarGen research on the MarGen blog.
Ready to become the brand AI cites by name? Book a free AI Citation Audit and Leeroy’s team will map exactly how your brand appears — or fails to appear — inside ChatGPT, Google AI Overviews, Perplexity, and Claude.