SEO, AEO and GEO: What Is the Difference, and Which Does Your Business Need?
The short answer
SEO gets a page found, indexed and ranked by Google and Bing, and earns a click. AEO shapes the page so an engine can lift a short answer out of it. GEO makes the page worth citing when ChatGPT, Gemini or Perplexity write an answer. They are one foundation and two formats, not three jobs, and the foundation comes first.
A Sydney business owner now gets three kinds of cold email about the same website. One offers SEO. One offers AEO, with a line about featured snippets and voice search. The newest offers GEO, and promises the business will be "recommended by ChatGPT". The acronyms are real and each describes something that exists. The implication that they are three separate jobs, needing three separate invoices, is not.
This post sets out what each term means, what the evidence says about how far they overlap, which parts of GEO are new and which are old SEO with a fresh name, and the order a business with one website and no marketing department should do them in. How to get your website cited by AI: what we changed on ours is the practical companion, written from this site's own rebuild; this one is the map.
What is SEO, and what does it still decide?
Search engine optimisation is the work of getting a page crawled, indexed, trusted and ranked by Google and Bing, so that a person searching for "emergency plumber Sutherland Shire" sees the page and clicks it. The parts of the job are familiar: pages whose text a crawler can read, a site that loads fast on a phone, a clear structure, words that match what people type, and links from other sites that signal the business is real. The goal is a click to your site.
SEO still decides more than the newer acronyms admit. Google AI Overviews, the AI summaries at the top of many Google results, draw many of their citations from pages that already rank, and how many is disputed. Ahrefs analysed 1.9 million citations from one million AI Overviews and reported on 21 July 2025 that 76% of cited pages ranked in Google's top 10 for the same query. Its updated study, reported by Search Engine Journal on 2 March 2026 from 863,000 keywords and four million AI Overview URLs, put the top 10 share at 38%, with 31% of citations from positions 11 to 100 and 31% from beyond that. Those two numbers disagree, and Ahrefs says why: the second study parses citations more thoroughly than the first, so the datasets are not directly comparable, and Google may be splitting one query into several related searches before choosing sources. Read together they say the same thing: a page that does not exist in Google's index at all is cited by nothing, and a page that ranks somewhere has a far better chance than one that does not.
The other engine matters more than most Sydney businesses think. ChatGPT search runs its web searches through third party engines including Bing, as InfoQ reported on 5 November 2024 at launch. A site that has never been submitted to Bing Webmaster Tools, or that blocks Bing's crawler, is invisible to ChatGPT's search however well it ranks on Google.
What is AEO, and why is it a format rather than a job?
Answer engine optimisation is formatting content so an engine can lift a direct answer out of it: a featured snippet at the top of Google, a "People also ask" box, a voice assistant reading one paragraph aloud, an AI Overview quoting one sentence. The content is structured to answer a specific question concisely. A heading phrased as the question. A short answer directly under it, complete in itself. Questions customers ask, published as questions with self-contained answers.
That is a way of writing, not a separate project. A service page that opens with the answer, says what the business is once in plain words, and carries its common questions as questions is doing AEO whether or not anyone calls it that. The pages on this site are written that way, and the shape of them is described in the companion post.
One AEO promise needs a correction, because agencies still make it. FAQ schema, the markup that labels a question and its answer for machines, used to expand a page's questions directly under its Google listing. Google changed that in August 2023: FAQ rich results are now shown only for what Google called well known, authoritative government and health websites, as Wordtracker reported on 20 August 2023 from Google's announcement. A tradie or a clinic adding FAQ markup will not get the expanded listing. The markup is still worth adding, for the second reason: it tells any machine reading the page which text is a question and which is its answer, which is the structure an assistant needs to extract the pair cleanly. Durbacti publishes FAQ pairs on its own pages for that reason and would not promise a rich result for them.
What is GEO, and which parts of it are new?
Generative engine optimisation is optimising for the AI chat tools, ChatGPT, Perplexity, Claude and Gemini, so that a site or a business is cited or recommended when one of them writes an answer. The term comes from a paper. Researchers from Princeton University, IIT Delhi and elsewhere published the paper that introduced the term at the KDD 2024 conference, testing a set of content changes across a benchmark of 10,000 queries. Their headline: the right changes "can boost visibility by up to 40%" in generative engine responses. The changes that worked were adding citations to sources, adding quotations from relevant sources, and adding statistics. The change that did not work was keyword stuffing, the oldest SEO trick there is, which scored below the unoptimised baseline.
So the new part of GEO is a content preference, and it is a preference for exactly the writing a careful business would publish anyway: sourced numbers, named quotations, original data, clear attribution, and a consistent description across the web of who the business is and what it does. The parts of GEO that are not new are the foundation underneath: a page the engine can fetch, parse and trust, which is SEO under its old name.
Two findings should temper what any GEO vendor promises. First, the engines do not agree with each other. Ahrefs compared the 50 most cited websites across Google AI Overviews, ChatGPT and Perplexity in June 2025 and found that only 14% of them were shared across all three, seven websites in total, published 12 June 2025. Being cited by one engine is not being cited by all of them. Second, the click a citation produces is rarer than the click a ranking produces. Pew Research tracked the browsing of 900 United States adults through March 2025 and reported on 22 July 2025 that users who saw an AI summary clicked a traditional result on 8% of visits, against 15% when no summary appeared, and clicked a link inside the summary on 1% of visits. Those are United States figures from Google only, so read them as the direction rather than the Sydney number; no equivalent Australian measurement was found for this post.
Which is the foundation, and what happens if you skip it?
SEO is the foundation because every other layer reads from it. An answer engine extracts from a page it has indexed. A generative engine cites a page its search provider returned. Neither can use a page that is assembled by JavaScript after load, blocked in robots.txt, missing from Bing, or so slow the crawler gives up.
The OpenAI bot documentation makes the dependency concrete. OpenAI's crawler page, read on 22 October 2026, describes OAI-SearchBot as the crawler for ChatGPT's search features and says sites that opt out of it "will not be shown in ChatGPT search answers, though can still appear as navigational links". It is a separate bot from GPTBot, the training crawler, and the page says each robots.txt setting is independent of the others. A business that blocked every AI bot in 2024 on principle, or whose web developer did, has opted out of ChatGPT search without knowing it. Whether to let the training crawler in is a different question with its own trade-offs, and one for another post.
Skipping the foundation looks like this: a business pays for GEO content, sourced and quotable, on a site Bing has never indexed, behind a JavaScript framework that renders the text after the crawler has left. The content is good. Nothing can read it.
Which should a Sydney business do first?
In order, and the order is by dependency, not by fashion.
SEO, the technical half. Text in the HTML. Fast on a phone. Indexed by Google and by Bing, checked in both consoles. One page per service, one clear statement of what the business is and where it works, the same on the site, the Google Business Profile and every directory.
AEO, as a writing habit. Every service page opens with the answer to the question it exists for. Headings are the questions customers ask. Common questions are published as questions with answers that stand alone, marked up so a machine can tell which is which.
GEO, as a standard for what gets published. Numbers carry their source and date. Claims are attributable. The business says the same thing about itself everywhere. Original material, a measurement the business made, a position it holds that competitors would hedge on, is worth more than a summary of someone else's page, because a summary is what the assistant is already producing.
That is also the order in which results arrive. Technical SEO shows in a console within weeks. AEO shows when a page starts appearing in a snippet or an Overview. GEO is the slowest and the hardest to see, for a reason the next section is about.
What nobody can measure yet
There is no rank tracker for "ChatGPT recommended us". A citation happens inside a conversation nobody else sees, differs between engines, differs between two people asking the same question, and moves when the model is updated. Tools now estimate it by running thousands of prompts and counting mentions, which is a sample of the tool's prompts rather than a measurement of your customers'.
What can be measured is narrower. Whether a page is indexed by Google and Bing. Whether the text is in the HTML. Whether an AI Overview has cited the page, found by running the search and looking. Referrals that arrive with a ChatGPT or Perplexity address in the analytics, which undercount because many arrive with none. And the oldest measure: whether the phone rings and the enquiry form fills, which is the only one that pays a bill.
Durbacti's own site is built the way this post describes, and the companion post says plainly that the before and after is not yet measurable there either. Anyone who shows a Sydney business a graph of its "AI visibility" should be asked what was counted and how.
What we will not do
Sell GEO as a separate package. A site Durbacti builds carries the foundation, the answer format and the citable content as one thing, because they are one thing.
Promise a citation. No vendor controls what ChatGPT, Gemini or Perplexity say, and the engines do not even agree with each other.
Stuff keywords. The one method the GEO research found to score below doing nothing.
Add FAQ markup to win a rich result that Google no longer shows most sites. The markup goes in for machine readability, and the client is told which of those two it is for.
Invent a statistic to look citable. A made-up number is the fastest way to be cited for the wrong reason, and this post carries none.
What to ask any agency selling SEO, AEO or GEO
Is our site indexed by Bing, and can you show us? A GEO pitch from someone who has not checked is a pitch for a house with no ground floor.
Is our text in the HTML with JavaScript off? Ask them to show you.
Which of these three are you selling separately, and why? The honest answer names one website.
Did Google change FAQ rich results in 2023, and what are you adding the markup for? Both halves should be answered.
How will you measure a citation, and what is the sample? Thousands of prompts someone else chose is an estimate, and should be described as one.
What on our site would an assistant quote that it could not get elsewhere? If the answer is a summary of other sites, nothing.
One website, built so a crawler can read it, written so an engine can answer from it, and sourced so a model can cite it. The Website development page describes how Durbacti builds that site, the same way it built its own; which of the three layers your site is missing is the first question on a free strategy call.
Common questions
What is the difference between SEO, AEO and GEO?
SEO, search engine optimisation, is the work of getting a page crawled, indexed, trusted and ranked by Google and Bing so that a person clicks through. AEO, answer engine optimisation, is formatting that page so an engine can extract a direct answer: a heading phrased as the question, a short answer under it, FAQ pairs that stand alone. GEO, generative engine optimisation, is making the page worth citing when ChatGPT, Gemini, Claude or Perplexity generate a response: sourced statistics, quotations, original data and a consistent description of who the business is. Each layer depends on the one before it.
Do I need a separate GEO agency as well as an SEO agency?
No. A generative engine can only cite a page it can fetch, parse and trust, which is the same page a search engine ranks. Google AI Overviews draw most of their citations from pages that already rank somewhere in Google, and ChatGPT search runs on third party engines including Bing, so a site absent from those indexes is invisible to both. What GEO adds is content work, not a new technical layer: sourced numbers, quotations, original data and a consistent entity description. A website built properly carries all three, and Durbacti builds them into one site rather than three packages.
Does FAQ schema still get a rich result in Google?
For most sites, no. Google announced in August 2023 that FAQ rich results would only be shown for well known, authoritative government and health websites, so a plumber or a dental clinic marking up its questions will not see them expanded under its listing. FAQ markup is still worth adding, for a different reason: it tells any machine reading the page which text is a question and which is its answer, which is what an AI assistant needs to lift the pair out cleanly. Durbacti publishes FAQ pairs on its own pages for that reason, not for a rich result.
Can you optimise for ChatGPT without optimising for Google and Bing?
Not in any way that works. ChatGPT search performs its web searches through third party engines including Bing, and OpenAI's own bot documentation says a site that opts out of its search crawler will not be shown in ChatGPT search answers. So the first requirement for appearing in ChatGPT is the ordinary one: a site Bing has indexed and the OAI-SearchBot crawler is allowed to read. Everything described as GEO sits on top of that, and a site that skips the foundation to chase citations is building the second storey of a house with no ground floor.
Which should a Sydney small business do first: SEO, AEO or GEO?
SEO, in the plain technical sense: a fast site whose text is in the HTML, indexed by Google and Bing, with one clear statement of what the business is and where. Then AEO, which is a writing habit more than a project: each service page answers the question a customer would type, in the first two sentences, with the questions customers ask published as questions. GEO comes last and is the slowest to show results, because it depends on sourced facts and on being mentioned elsewhere. Durbacti builds all three into a site from the start, in that order.