Three acronyms are now sold to Australian businesses as three different services. SEO gets you ranked. AEO gets you answered. GEO gets you into whatever the AI writes. Agencies price them separately.
We wanted to know whether they are actually three different jobs, so we measured it. In August 2026 we ran 20 real Australian buying searches through four places at once: Google’s normal results, Google AI Mode, ChatGPT and Perplexity. Then we compared which websites each one used.
They agree far less than the marketing suggests. Only 21% of the sites ChatGPT cited were on Google’s first page for the same search.
But the fix for that is not three separate retainers. Here is what the data actually shows.
What the three acronyms mean
| Term | Stands for | The goal |
|---|---|---|
| SEO | Search engine optimisation | Rank in the list of blue links |
| AEO | Answer engine optimisation | Be the source a direct answer is built from |
| GEO | Generative engine optimisation | Be named inside an AI written answer |
AEO and GEO describe nearly the same thing. AEO is the older term, from the days of featured snippets and voice assistants. GEO arrived with ChatGPT. In practice, when an Australian agency sells you either one, the work is the same work.
SEO is genuinely different. It is about a ranked list. The other two are about being quoted.
The test
We took 20 searches a customer types when they are ready to hire. “Best electrician perth”. “Custom home builder brisbane”. “How much does it cost to build a house in australia”. Solar, legal, building, trades, dental, finance, physio, removals and marketing.
Each one went to four places with an Australian setting: Google organic results, Google AI Mode, ChatGPT with web search on, and Perplexity. We recorded every website each one used, then checked the overlap.
Result one: the four surfaces mostly disagree
| Surface | Sites used | Also on Google page one | Searches using nothing from page one |
|---|---|---|---|
| Google AI Mode | 162 | 40% | 0 of 17 |
| Perplexity | 322 | 30% | 0 of 18 |
| ChatGPT | 67 | 21% | 7 of 18 |
On 7 of those 18 searches, ChatGPT built its entire answer without touching a single site from Google’s first page. AI Mode and Perplexity always used at least one.
Even Google’s own two products disagree. Only 13% of ChatGPT’s citations also appeared in Google AI Mode’s answer for the same search.
So the premise behind selling GEO separately is real. Ranking is not the same as being cited.
Result two: each engine has a personality
This is where it gets useful. The engines do not just disagree, they disagree in consistent ways.
| Source type | Google organic | Google AI Mode | ChatGPT | Perplexity |
|---|---|---|---|---|
| Business websites | 77% | 82% | 75% | 83% |
| Directories and review sites | 11% | 8% | 12% | 12% |
| Forums | 8% | 4% | 1% | 4% |
| Government and education | 3% | 4% | 12% | 1% |
| Social media | 2% | 2% | 0% | 1% |
Two things stand out.
ChatGPT leans on government sources four times harder than anyone else. 12% of its citations were .gov.au or equivalent. When we looked at the searches it runs behind the scenes, the reason was obvious. It writes queries like site:legalaid.nsw.gov.au car accident claim lawyer and site:cleanenergycouncil.org.au approved solar retailer melbourne. It goes looking for an official register first.
Perplexity is a volume machine. It cited 322 sites across those searches, an average of 17.9 per answer. ChatGPT averaged 3.7. If you want to appear in Perplexity, there are simply more slots. If you want to appear in ChatGPT, there are four.
| Surface | Sources per answer |
|---|---|
| ChatGPT | 3.7 |
| Google AI Mode | 9.0 |
| Perplexity | 17.9 |
Perplexity also cited reddit.com in 13 of its 20 answers. ChatGPT cited a forum once in the entire study.
Result three: the work overlaps even when the results do not
Here is the part the three-acronym pitch skips over. The engines disagree about which sites to use, but they agree almost completely about what kind of site to use. Business websites were 75% to 83% of citations everywhere, including on Google’s normal results page.
Which means the underlying job is shared. Every one of these surfaces is trying to find a page that makes a checkable claim, on a site it can fetch, from a business it can verify elsewhere.
You do not do that three times.
| Work | Helps SEO | Helps AEO and GEO |
|---|---|---|
| Being fetchable by crawlers | Yes | Yes |
| Clear service and location pages | Yes | Yes |
| Specific claims in plain page text | Some | Yes |
| Reviews and third-party listings | Some | Yes |
| Link building | Yes | Indirect |
| Keyword targeting and title tags | Yes | Little |
| Being on the right register or directory | Some | Yes, especially ChatGPT |
The honest summary: most of the work is shared, and the rest is publishing facts and getting listed in the places each engine trusts.
The site that shows why this matters
One domain, starworks.com.au, was cited seven times by ChatGPT and five times by Perplexity across our searches. It is a small Australian listing site. It does not rank on page one for most of the terms where it got cited.
We saw the same pattern in testing earlier this month. A site with modest Google rankings can carry an outsized share of AI answers, because AI reaches for lists it can quote names from. If your competitors are on it and you are not, that gap does not show up anywhere in your rank tracker.
So do you need GEO, AEO or SEO?
Our reading of the data, plainly:
- Keep doing SEO. It is still the best single predictor of being cited. Four in ten of AI Mode’s sources came from Google page one, and it remains the only one of these surfaces where you can actually track position.
- Treat AEO and GEO as one thing. They are. If someone quotes you for both, ask what is different between them.
- Start with fetchability and facts. These are cheap and they help every surface at once.
- Pick your engine. If your customers use ChatGPT, get on the official registers and directories in your industry. If they use Perplexity, reviews and forum presence matter more.
- Do not buy three retainers. There is one job here with a lot of shared plumbing.
We have written more on the mechanics in what answer engine optimisation actually is, and on the Google side in our Google AI Mode study. If you want your own numbers rather than ours, that is what our generative engine optimisation work measures first.
Common questions
What is the difference between GEO and SEO?
SEO aims to rank your page in a list of links. GEO aims to get your business named inside an AI written answer. They are related but not the same. In our test only 21% to 40% of the sites AI engines cited were on Google’s first page for the same search.
Is AEO the same as GEO?
In practice, yes. AEO is the older term and GEO is the newer one, but the work an agency does under either label is close to identical. The real differences are between engines, not between acronyms.
Does GEO replace SEO?
No. Google AI Mode drew 40% of its sources from Google’s own top 10, the highest overlap of any AI surface we tested, and it used at least one page-one site on every search. Ranking still helps more than anything else we can measure.
Which AI engine is easiest to get cited by?
Perplexity, on volume alone. It cited 17.9 websites per answer against ChatGPT’s 3.7. ChatGPT is the hardest, and it favours official registers and government sources.
Why does ChatGPT cite so many government websites?
Because it searches for them on purpose. Its behind-the-scenes queries repeatedly used site: searches aimed at government and industry body domains before looking at businesses. For regulated trades, being on the relevant register matters.
How much of my SEO work already counts as GEO?
Most of the technical and content foundations do. What usually does not carry over is keyword-led title tag work. What is usually missing is publishing specific, checkable facts in plain text on the page.
Can I track GEO the way I track rankings?
Not with the same confidence. AI answers move a lot between identical searches, so a single check is a snapshot rather than a position. Tracking across a set of real customer questions over time is more reliable than any one result.
Method: 20 Australian commercial and research searches run in August 2026 through Google organic results (desktop, top 20), the Google AI Mode SERP API, ChatGPT with web search enabled and Perplexity, all set to Australia. Overlap is measured at domain level against Google’s top 10 organic results, across the 18 searches that returned a usable organic list. Google’s own internal preview links were excluded.
