AEO vs SEO: what changed and what to do about it

The marketing team you hired in 2022 is good at SEO. They have backlinks, they have keyword research, they have a content calendar. So why is your brand missing from every ChatGPT recommendation?

Because Answer Engine Optimization (AEO) is not just rebranded SEO. The signals overlap but the algorithms are different, the distribution is different, and increasingly the user journey is different. This post lays out the comparison cleanly, then gives you a 30-day migration plan you can hand to your existing team.

The one-sentence version

SEO is winning the click. AEO is winning the synthesis.

Google sends users to ten ranked links; the user clicks one. ChatGPT sends users one answer; whether your brand is in that answer is binary.¹ Optimising for a ranking on a SERP and optimising for inclusion in a synthesised paragraph are related — but they are not the same job.

Example: real AI mentions of InsiteChat with sentiment — the AEO outcome a rankings report can't show. FixAEO.

How the signals differ

Signal	SEO weight	AEO weight	Why the gap
Backlinks	Very high	Medium	AI engines weight source authority (Wikipedia, industry pubs) over raw link count
Keyword density	Medium	Low	Models read meaning, not n-gram frequency
Page speed	Medium	Low	Crawlers don't bounce; LCP doesn't help retrieval
Schema.org markup	Medium	Very high	JSON-LD is how the model decodes "what is this site"
Question-style headings	Medium	Very high	RAG retrieval favours pages that pre-answer the user's prompt
Fresh content	Medium	High	LLM citation systems prefer recent sources
llms.txt	None	High	New standard, only AEO uses it2
Citations from authoritative sites	High	Very high	Wikipedia mention can outweigh 1,000 backlinks
robots.txt allowing AI bots	Neutral	Critical	Block GPTBot/ClaudeBot and you're invisible

The bold rows are where most teams are losing ground today.

The three eras of search optimisation

A useful lens:

Era 1 — Keywords (2000–2012)

Match the user's search string with on-page tokens. Optimise titles, meta descriptions, and exact-match domains. The page that mentioned the keyword most plausibly won.

Era 2 — Intent (2012–2024)

Google's RankBrain³ and BERT reframed the problem: serve the result that satisfies the underlying intent, even if the keywords don't match. Backlinks, EEAT, schema markup, page experience signals. The page that answered the question best won.

Era 3 — Synthesis (2024–now)

AI assistants don't link to a page — they summarise the consensus. The page that feeds the synthesis wins. Often that means:

• being on the first SERP (so the retrieval layer picks you up)⁴
• being cited by an authoritative third party (so the model gives your claim weight)
• having structured data the model can decode reliably⁵
• being machine-readable on purpose (llms.txt, FAQ schema)

If you stopped at Era 2 you are not visible in Era 3.

Example: ChatGPT (logged out) naming the tools in a category. This is the AEO surface a Google rankings report never shows you.

A 30-day AEO migration plan for an SEO team

Most marketing teams already do steps 1-3 for SEO. They are repurposable. The gaps are in steps 4-6.

Week 1 — Foundations

1. Audit robots.txt. Confirm GPTBot, ClaudeBot, Google-Extended, PerplexityBot, anthropic-ai, and CCBot are not blocked. The default User-Agent: * covers them, but many sites have explicit blocks left over from 2023 panic.⁶ While you're there, validate your sitemap.xml so crawlers can actually discover every page.
2. Run a free AEO scan. FixAEO's free scanner checks 10 heuristics plus live LLM brand queries in ~5 seconds.
3. Add an Organization JSON-LD block to the homepage. Include name, description, logo, sameAs (LinkedIn, X, Crunchbase), email.

Week 2 — Content

4. Convert your top 5 SEO pages into answer-shaped content. Replace product-marketing H1s with the actual question users ask. "Best CRM for indie SaaS" is a better H1 than "Our CRM".
5. Add FAQPage JSON-LD to anywhere that has Q&A content. AI assistants lift Q&As verbatim from this schema.

Week 3 — Distribution

6. Publish /llms.txt at the site root. Five-minute job: a Markdown manifest describing your business, products, and key pages.² Follow the step-by-step llms.txt guide.
7. Earn one Wikipedia mention (if eligible). It's the single highest-ROI citation in AEO.

Week 4 — Measurement

8. Define your tracked prompts. The 20 questions your buyers ask AI assistants before they reach your site.
9. Baseline your Visibility Score (the share of AI answers that mention you) across 5 engines (ChatGPT, Claude, Copilot, Gemini, Perplexity). Anything below 40% is a problem.
10. Set a 30-day improvement target. AEO score from N to N+15 is realistic if you do steps 1-9 above. Use our AEO ROI calculator to translate that score change into expected pipeline impact.

Should you stop doing SEO?

No. The mistake is treating AEO as a replacement. Treat it as the third channel in your acquisition stack, alongside SEO and paid.

Channel	What it gets you	Time-to-result
SEO	Direct clicks, indexable depth, branded queries	3–9 months
Paid search	Immediate top-of-page on commercial intent	Days
AEO	Inclusion in AI syntheses, citation surface on Perplexity/Gemini, "trusted recommendation" effect	4–12 weeks

The SEO investments compound into AEO automatically. The reverse is also partially true. They are not in conflict.

FAQ

Is AEO just a fad?

Unlikely. Three of the four major AI assistants now have first-party search products,¹ and structured-data citation systems are only getting more sophisticated. Even if a specific engine fades, the underlying optimisation — clear content, machine-readable schema, citation building — is durable.

Will AEO replace SEO?

No. SEO and AEO have different distribution surfaces (Google vs AI assistants) and slightly different signals. Treat them as complementary.

How long until AEO investments show results?

Faster than SEO. Schema.org changes are picked up in days; new llms.txt files within a week; LLM training data takes 6–12 months but real-time retrieval (the bigger lever) responds immediately.

What's the simplest AEO improvement I can make today?

Add /llms.txt to your site root and make sure robots.txt doesn't block AI crawlers. Five minutes of work; both are zero-downside. See how to add llms.txt.

How do I measure AEO?

Track Visibility Score (% of relevant prompts that mention you across N engines) and sentiment (-1 to +1 tone score). Run weekly — FixAEO does this automatically.

In one paragraph

AEO is the third era of search optimisation. SEO targets Google's ranking; AEO targets AI assistants' synthesis. The signals overlap (schema, content quality, authority) but the weights are different (structured data >> backlinks; question-form headings >> keyword density). If you're already doing SEO well, you have 60% of the work done — but the missing 40% is where your competitor is winning today.

Run a free FixAEO scan to see exactly where you sit on the AEO curve. Takes 30 seconds, no signup.

Footnotes

1. OpenAI: Introducing ChatGPT search. Read the announcement. ↩ ↩²

2. llmstxt.org: The /llms.txt file. Read the spec. ↩ ↩²

3. Google: How Google Search works. Read the explainer. ↩

4. OpenAI Help Center: How ChatGPT search works. Read the help article. ↩

5. Google Search Central: AI features and your website. Read the AI features guidance. ↩

6. Google Search Central: Introduction to robots.txt. Read the robots.txt guide. ↩