GEO & SEO consultant: get your business cited by AI
Your customers are asking ChatGPT, Perplexity, Gemini, Claude and Google's AI Overviews. I make sure the answers mention your business, with a measurable method and tools I built myself.
- In search since 2011. Independent consultant since 2014.
- Creator of Éclair CMS. And of Arachnide SEO Spider and Vigie: three open-source programs.
- Author of La Bible de Claude AI. An Amazon best-seller, in six languages.
- 30,000+ followers. On LinkedIn.
Your customers no longer search only on Google
A growing share of searches end in an AI-written answer, often without a click to any website. If your business isn't cited in that answer, it doesn't exist for that customer. The latest figures confirm it:
- 48% of French people aged 12 and over use generative AI, up 15 points in one year (Arcep and CREDOC, Baromètre du numérique 2026).
- 37.9% of Spaniards aged 16 to 74 used a generative AI tool in the last three months (INE, TIC-H survey 2025).
- 900 million people use ChatGPT every week (OpenAI, February 2026, via TechCrunch).
- Google's AI Mode has passed 1 billion monthly users (Alphabet, Q2 2026 results).
- When Google shows an AI summary, users click a classic link in 8% of visits, versus 15% without a summary (Pew Research Center, July 2025).
SEO remains the foundation. GEO adds the layer that turns your site into a source AI engines reuse. To measure how AI summaries affect your traffic, read my analysis Google AI Overviews: What 2026 Studies Really Say About Your Traffic.
What is GEO?
GEO (Generative Engine Optimization) covers the techniques that increase the likelihood of an AI answer engine (ChatGPT, Perplexity, Gemini, Claude or Google's AI Overviews) citing your site, your brand or your products. It builds on SEO, which makes your pages crawlable and indexable, and adds three requirements: content that's easy to extract, a clear and consistent entity, and evidence confirmed by other sources.
| Criterion | SEO | GEO |
|---|---|---|
| Goal | Rank your pages in the results | Be cited in the generated answer |
| What you measure | Rankings, clicks, traffic | Citations, brand mentions, share of voice in AI answers |
| Main levers | Technical, keywords, links | Direct answers, sourced evidence, consistent entity, mentions on other sites |
Three ways to work together
GEO Audit
Know what AI says about you, who gets cited instead of you and what to fix first. From €300 excl. VAT. Discover the GEO audit
AI Search Optimization
A monthly service to become a source ChatGPT, Perplexity and Google cite. From €800 excl. VAT per month. Discover the monthly service
GEO Training
A hands-on day to make your team autonomous at getting cited by AI. From €1,500 excl. VAT per day. Discover the training
Need a solid technical foundation first? Discover my technical SEO consulting work or compare all services on the Pricing page.
How I make a business citable by AI
Measure
I test the questions your customers actually ask in ChatGPT, Perplexity, Gemini, Claude and Google, and record who gets cited.
Fix the technical base
Crawling, indexing, HTML rendering, speed, structured data, AI crawler access: I fix whatever prevents engines from reading your site.
Make your content citable
Direct answers, definitions, sourced figures, tables, FAQs: I rewrite the pages that matter in the format AI engines reuse.
Build authority
Consistent profiles, mentions on reference sites, client reviews: AI engines more readily repeat what other sources confirm.
Monitor and adjust
Every month, I re-measure the same questions with Vigie and show you what moved, with evidence.
My evidence is public
I'm not asking you to take my word for it. I apply my methods to my own software, websites and books, all public and verifiable.
- Éclair CMS: the CMS I created, with no database, 100/100 on Lighthouse, and SEO and GEO built in (llms.txt, a Markdown version of every page, GEO score). This site runs on it.
- Arachnide SEO Spider: a free, open-source SEO crawler, an alternative to Screaming Frog, with JavaScript rendering, log analysis and AI crawler checks.
- Vigie: an open-source tracker of a brand's visibility in AI assistant answers.
- La Bible de Claude AI: my reference guide to Claude AI, a best-seller on Amazon, published in six languages.
- GustinAI and DelfOnline: my AI training business and my DELF exam-prep platform, designed and optimized for search on my own.
Who is Thierry Gustin?
I've worked in search since 2011 and as an independent since 2014, between France and Spain, from Madrid. My path has been anything but linear: optician, WordPress and SEO consultant, chef, then author and software builder. Today I run several activities on my own, with AI as my team: you always speak to the person doing the work. Discover my background.
Latest blog posts
My Vision of SEO and GEO for 2027: Seven Theses and an Action Plan
SEO in 2027: my vision of SEO and GEO in seven sourced theses, the 2026–2027 timeline and the action plan small businesses should start right now.
How Much Electricity Does a Website Use? Éclair and WordPress in Numbers
Website energy consumption: the SWD v4 method, Eurostat prices, CO2 in France and Spain, and a transparent Éclair vs WordPress calculation.
Every article, with its sources, is on the SEO and GEO blog.
Based in Madrid, I work with businesses across Europe and North America. For US companies, see GEO consulting in the United States; in Spain, consultor GEO en España.
Frequently asked questions about GEO
What's the difference between SEO and GEO?
SEO aims to rank your pages in Google's results. GEO aims to get your brand cited in AI-generated answers. The two complement each other: a poorly crawled or poorly indexed page is unlikely to be cited, and a well-ranked page isn't necessarily picked up by an AI if it doesn't answer the question clearly.
How long does it take to get cited by ChatGPT or Perplexity?
Engines that search the web in real time, like Perplexity, ChatGPT with search or Google's AI Overviews, can pick up a page as soon as it's crawled and indexed, sometimes within a few weeks. Presence in a model's internal knowledge depends on its training cycles, so it takes several months.
Can anyone guarantee appearing in AI answers?
No. Nobody controls an AI model's answers, and any promise of guaranteed results should raise a red flag. I commit to a method, documented actions and an honest measurement of how your visibility evolves.
How much does a GEO audit cost?
My GEO audit starts at €300 excl. VAT for a single-language brochure site. The price depends on the number of pages, languages and questions to test. You receive a fixed quote after a 30-minute call.
Do you work in France and Spain?
Yes. I'm based in Madrid and work in French, Spanish and English for companies in both countries, remotely, or on-site for training.
Do you need an llms.txt file to be visible in AI?
It's not essential. Google states that no special file or markup is required to appear in its AI features. An llms.txt doesn't hurt and may help some tools, but it's no substitute for a well-crawled site, clear content or a recognized brand.
All the other answers are in the GEO and SEO FAQ.
Find out what AI says about your business
In 30 minutes, I'll live-test a few key questions from your market across the main AI engines and tell you where to start. No commitment, in English, French or Spanish.
Book your 30-minute call
A direct conversation, free and with no commitment.