What Is AEO? Answer Engine Optimization Explained Simply
Searching the internet is changing fundamentally. Instead of working through a list of blue links, more and more people are putting their questions directly to AI systems such as ChatGPT, Perplexity, Google AI Overviews or Gemini — and expecting a ready-made answer. For businesses, this means: traditional SEO alone is no longer enough. Welcome to the world of Answer Engine Optimization (AEO).
What is AEO and how does it differ from SEO?
AEO stands for "Answer Engine Optimization" — optimising your content for AI-based answer systems. While traditional SEO aims to appear as high up as possible in Google's search results, AEO aims to be cited as a source by AI systems when users ask questions.
The difference is fundamental: with SEO, you compete for a position on a list of results. With AEO, you compete to be the answer itself — or at least to be named as the source of the answer.
According to a widely cited forecast by Gartner, traditional search engine volume will fall by 25% by 2026 as consumers increasingly use AI chatbots and virtual agents (Source: Gartner, February 2024). This does not mean that Google will disappear — but it does mean that a growing share of search queries is going through new channels that require different optimisation strategies.
How do AI search systems work?
To understand AEO, we first need to understand how AI search systems work. Unlike Google, which indexes websites and sorts them by relevance, AI search systems work in a fundamentally different way:
ChatGPT (with browsing)
ChatGPT can search the internet in real time, summarise information from various sources and deliver a structured answer. Sources are linked when the browsing function is active. According to SimilarWeb, ChatGPT has more than 1.5 billion monthly visits (as of 2025) and is used by millions of people as an alternative or complement to Google.
Perplexity AI
Perplexity is an AI search engine specifically designed to answer questions with source-based answers. Every answer contains numbered source references that link directly to the original websites. For website owners, this means: if your page is cited as a source, you receive direct traffic.
Google AI Overviews (formerly SGE)
Google itself is increasingly integrating AI-generated answers directly into its search results. These "AI Overviews" appear above the traditional search results and summarise information from various sources. According to Search Engine Land, AI Overviews are already shown for a significant share of Google search queries in the USA and are increasingly being rolled out to other markets.
Gemini (Google)
Google's AI assistant Gemini can answer questions while drawing on Google search results and other sources. As Google's direct competitor to ChatGPT, Gemini is increasingly being integrated into Google products.
Why are some websites cited by AI and others not?
AI systems do not choose their sources at random. They prefer content that meets certain criteria:
- Clear, direct answers: content that answers questions precisely and in the first few sentences is preferred
- Structured data: websites with Schema.org markup and a clear HTML structure are easier for AI to process
- Authority and trustworthiness: websites with demonstrable expertise, citations and reputable sources are referenced more often
- Timeliness: up-to-date, regularly refreshed content is preferred over outdated pages
- Primary sources: original research, your own data and case studies take precedence over retold content
Rand Fishkin, founder of SparkToro and one of the world's leading SEO experts, stresses: "The future does not belong to websites that are optimised for algorithms, but to those that are regarded as a primary source — original sources of information that others refer to." (Source: SparkToro Blog)
The 7 most important AEO measures
1. Implement structured data (Schema.org)
Structured data helps AI systems understand your website's content. With Schema.org markup, you can tell Google and AI crawlers what your page contains: is it a business? A product? An FAQ? An article?
The most important schema types for SMEs:
- LocalBusiness: name, address, opening hours, contact details
- FAQPage: frequently asked questions with answers
- Article: blog articles with author, date, category
- Product / Service: products and services with prices
- Review / AggregateRating: customer reviews
According to a study by Search Engine Journal, structured markup increases the chance of a featured snippet (position 0) on Google by up to 40% — and featured snippets are often the basis for AI answers.
2. Create FAQ sections with clear answers
AI systems love FAQ sections because they can extract question-and-answer pairs directly. Create FAQ sections on your most important pages that answer your target audience's most frequent questions.
How to write AEO-optimised FAQs:
- Phrase the question as an H3 heading (e.g. "How much does a website cost?")
- Give the answer directly and precisely in the first sentence
- Then add details and context
- Use FAQ schema markup
3. Create an llms.txt file
The llms.txt is a relatively new concept — a file in your website's root directory (similar to robots.txt) that is intended specifically for AI systems. It contains a machine-readable summary of your business, your services and your expertise.
While there is no binding standard yet, several AI search systems have already signalled that they evaluate llms.txt files. It is a low-effort measure that you can implement now to be prepared for the future.
4. Cite authoritative sources
AI systems also assess the credibility of content based on the sources it cites. If your content refers to reputable sources — studies, official statistics, recognised industry experts — the likelihood that your page will be classified as trustworthy and cited increases.
Tip: Link to primary sources (e.g. the original study) rather than to third-party summaries.
5. Strengthen E-E-A-T signals
E-E-A-T stands for Experience, Expertise, Authoritativeness and Trustworthiness — the quality criteria by which Google and AI systems assess content. For SMEs, this specifically means:
- Experience: show practical experience — case studies, project examples, before-and-after images
- Expertise: publish specialist articles, show qualifications and certifications
- Authoritativeness: become a cited reference in your industry. Guest articles, interviews and press releases help
- Trustworthiness: Impressum (legal notice), privacy policy, SSL encryption, customer reviews, transparent contact details
6. Open robots.txt to AI crawlers
Some website owners block AI crawlers such as GPTBot (OpenAI), ClaudeBot (Anthropic) or PerplexityBot in their robots.txt. That is understandable — but it also means that these AI systems cannot process your content or recommend your business.
Our recommendation: Allow AI crawlers to access your public content. The risk is low (the content is public anyway), while the potential benefit from citations and referral traffic is considerable.
7. Position your content as a primary source
The most valuable content for AI systems is original information: your own studies, your own data, your own first-hand reports, unique industry insights. If you are the first to publish a particular piece of information, you become the primary source — and AI systems prefer to cite primary sources.
Examples of primary-source content:
- Your own surveys and their results
- Industry-specific benchmarks from your own practice
- Detailed case studies with concrete figures
- Expert opinions and forecasts from your field
AEO checklist for businesses
| Measure | Priority | Effort |
|---|---|---|
| Implement Schema.org markup | High | One-off, 2–4 hours |
| Create FAQ sections with schema | High | 2–3 hours per page |
| Create an llms.txt file | Medium | 30 minutes |
| Optimise E-E-A-T signals | High | Ongoing |
| Check robots.txt for AI crawlers | Medium | 10 minutes |
| Add source references to content | Medium | 30 minutes per article |
| Create primary-source content | High | 4–8 hours per article |
AEO and SEO: not an either-or
It is important to understand: AEO does not replace SEO, it complements it. Most AEO measures — structured data, high-quality content, E-E-A-T — improve your Google ranking at the same time. So it is not a question of "either SEO or AEO"; both belong in a modern online marketing strategy.
According to Search Engine Journal, the overlap between SEO best practices and AEO requirements is greater than 80%. If you are doing good SEO, you already have a solid foundation for AEO.
Adlegio: AEO as a service
At Adlegio, we recognised AEO early on as a strategically relevant topic. Our websites are developed from the ground up to be optimised both for traditional search engines and for AI systems:
- Structured data: Schema.org markup is standard on every Adlegio website
- Performance: fast loading times improve both SEO and crawlability for AI systems
- Clean architecture: Django-based websites with a clear HTML structure are easier for AI to process than plugin-overloaded WordPress sites
- Content strategy: we help you create content that is positioned as a primary source
Conclusion: the future of search has already begun
AEO is not a topic for the future — it is relevant now. Millions of people already use AI search systems every day, and this trend will accelerate. Businesses that optimise their content for AI systems now will secure an advantage over competitors who sleep through this change.
The good news: the most important AEO measures are neither expensive nor technically complex. Structured data, clear FAQ sections, authoritative sources and E-E-A-T signals — you can put these basics in place today. If you are cited as a source by ChatGPT, Perplexity and Google AI, you gain visibility, trust and customers — free of charge and sustainably.
Would you like to optimise your website for AI search? Contact us — we will develop an AEO strategy that suits your business.