SEO
Ten results, the reader compares
Your page ranks somewhere in a list of links. The position determines the chance of a click. Progress shows up in rankings you can track week by week.
Answer engine optimisation
AEO agency for answer engine optimisation
21x is an AEO agency focused on one question: does ChatGPT, Gemini or Perplexity name your company when a customer asks for advice? Answer engine optimisation is the work that makes that more likely, across six AI systems. 21x measures where you stand before it changes anything.
An AEO agency works on the chance that answer engines such as ChatGPT name your company. 21x first measures this with 30 customer questions in six AI systems, then fixes what scored weak.
30 non-branded customer questions · Six AI systems, each question 3 times · Reported per system · No positions or guarantees sold
Source: IAB, Measuring Visibility in the AI Era, August 2026Updated:
The difference with SEO
AEO vs SEO: a list of links against one answer
Search engine optimisation competes for a place in a list of results, and the reader then chooses. With an answer engine, the choice is made before the reader sees anything. The system names a few companies, and the rest do not appear.
AEO
One answer, a few names
The answer names a handful of companies, or none at all. A company that is not named is not considered. The answer also differs per system and each time the question is asked.
The foundation overlaps: both need a site that crawlers can read and sources that others trust. The outcome differs, so a ranking report says little about answer engines. AEO therefore needs its own measurement, repeated over time.
AEO, GEO and AI SEO
Three names for work that largely overlaps
Answer engine optimisation (AEO, written optimization in American English) is a term many marketers use. It describes making your company part of the answer a system gives, instead of one link among ten.
Generative engine optimisation (GEO) is the term used in research, including the controlled study published at KDD 2024. AI SEO is the broadest label, and some agencies also use it for content written with AI tools.
For a company, the three terms describe the same work:
- Making sure AI crawlers such as GPTBot and ClaudeBot can read your site.
- Keeping your company details consistent wherever they appear.
- Being present on the platforms and sources that answers draw on.
- Writing pages that state facts clearly and cite their sources.
21x uses GEO in its research and AEO where that is the word you search for. The measurement and the work behind both are the same.
How it works
From 30 questions to a monthly re-measurement
Each step ends with a result you can check. You can stop after any step.
Agree on the questions
You describe your offer, your customers and your competitors. 21x then writes 30 non-branded questions that a buyer asks before they know your name. For English-speaking markets they are in English, phrased the way English-speaking customers ask; for the Dutch market they are in Dutch.
Measure in six answer engines
The questions go to ChatGPT, Claude, Gemini, Perplexity, Google AI Overviews and Microsoft Copilot. Each question is asked 3 times, logged out and with memory off. That makes 540 answers.
Assess every answer
Each answer is assessed on mention, position, sentiment, source and facts. You see where you are named, how you are described and which sources the answer relies on.
Fix what scored weak
The audit becomes a list of tasks, such as crawler access, company details, presence on key platforms and clearer pages. The work covers only the points that scored weak.
Measure again every month
The same questions, the same systems and the same counting rules. You see movement over time instead of a single snapshot.
What you get back
One question, six answer engines, six different outcomes
Example with fictitious data. The panel shows how often one company was named for one question, across 3 measurement moments per system.
The spread between systems is the point. A test in one system says nothing about the other five. That is why 21x reports per system and never as one combined score.
UpciteExample
Question
Which accountancy firm in Manchester advises tech start-ups on R&D tax relief?
- ChatGPT3 of 5 named
- Claude4 of 5 named
- Perplexity5 of 5 named
- Gemini2 of 5 named
- Microsoft Copilot1 of 5 named
- Google AI Overviews0 of 5 named
Named in
15 of 30
answers to this question, across six systems and 3 moments. A system that names no company at all does not count as a negative mention.
What it costs
AEO services in three phases, each with its own price
You can start with the audit and stop there. What follows depends on what the audit found, and you know the cost before work starts.
21x
Know where you stand
Basecamp
Insight into 9 areas, 3 to 5 priorities and advice on your next step.
€295one-off
excl. VAT
Wat zit erin?
- Scorecard on 9 GEO areas
- Technical check: schema, robots.txt, sitemap and llms.txt
- 30 questions, each asked 3 times, on 6 AI platforms
- PDF with concrete improvements
- 30 minutes together through the report
- Analysis without implementation
5 to 7 working days
Discuss Basecamp21x
Fix the foundation
Climb
Basecamp plus implementation of the most important improvements to your website.
€695one-off
excl. VAT
Wat zit erin?
- Full Basecamp included (€295)
- Baseline and follow-up measurement after 4 weeks
- Sharpen business profile, content and structure
- Basic structured data and answer blocks
- Check crawler access and sitemap
- Improve internal links on main pages
10 to 14 working days
Discuss Climb21x
Take a bigger step
Summit
A complete improvement round for your most important pages, with an agreed scope.
€1,995one-off
excl. VAT
Wat zit erin?
- Analysis and implementation included
- Improve business profile and key pages
- Answers to 10 important customer questions
- Technology, AI access and speed
- Before and after measurement: 30 to 50 questions, each asked 3 times
- Weekly update and a 30 minute call
- Delivery advice and plan for what comes next
3 to 6 weeks
Discuss Summit21x
Keep climbing
Altitude
Digital PR, monthly measurements and upkeep of the information about your business.
€695/ month
excl. VAT
Wat zit erin?
- Baseline and monthly measurement on 6 AI platforms
- Research into the sources AI uses
- Profiles, pitches, press releases and listings
- Quarterly comparison with competitors
- Maintain schema, llms.txt, business facts and crawler access
- Monthly report with work and next steps
- Upcite account included (not charged separately)
Minimum 3 months
Then cancel monthly
You can stop after any phase. What you build in one phase stays yours.
Why one system is not enough
The answer engine market is split
AEO aimed at ChatGPT alone leaves out a large part of the market. These are the estimated shares of AI chatbots in July 2026.
51.3%
estimated market share of ChatGPT among AI chatbots
Bron: First Page Sage, July 2026
27.7%
estimated market share of Gemini, the second largest
Bron: First Page Sage, July 2026
10.3%
estimated market share of Claude
Bron: First Page Sage, July 2026
Almost half of the market sits outside ChatGPT. Google AI Overviews and Microsoft Copilot also answer questions inside products people already use. That is why 21x measures six systems and reports each one separately.
Questions
What people ask about AEO
What does an answer engine optimisation agency do?
It works on the chance that AI systems name your company when a customer asks for advice. That covers crawler access, consistent company details, presence on the sources these systems use and clear pages. A good agency measures before and after, per system.
Is AEO the same as GEO or AI SEO?
Largely, yes. AEO is the marketing term, GEO the research term and AI SEO the broadest label. The work behind them is the same: being readable, recognisable and present where AI systems find their information.
AEO vs SEO: do I need both?
In most cases, yes. According to Cloudflare Radar, Google still sent more than 87% of all search referrals to websites in July 2026. SEO keeps that traffic coming in, and AEO covers the answers people read before they click anywhere.
What do AEO services cost?
That depends on what the audit finds, the size of your site and the competition in your market. You know the cost before any work starts, and you can stop after each phase. See the packages for what each phase includes.
Can you guarantee that ChatGPT will recommend my company?
No. Answers change each time a question is asked and whenever systems refresh their sources. Google's own guidance states that nobody can guarantee a first position in search, and nobody controls AI answers either. 21x sells a measurement and the movement in it, not a place.
Who will I work with?
With Stan Vreuls, founder of 21x in Maastricht, the Netherlands. He has eleven years of SEO experience and has also focused on AI visibility since January 2026. You speak to the specialist directly, not to an account manager.
Next step
Find out what answer engines say about you today
Stan Vreuls, Founder of 21x
A short call is enough to judge whether an audit makes sense for your company. If it does not, you will hear that too.
stan@21x.nl