GEO vs SEO: what generative engine optimisation changes and what it keeps
Generative engine optimisation (GEO) is the practice of making a brand visible inside AI-generated answers. Search engine optimisation (SEO) is the practice of making a brand visible on search results pages. The two disciplines share a foundation and diverge at the point of retrieval: SEO competes for a ranked position and a click, while GEO competes for a citation or a mention inside the answer itself (Search Engine Land).
Third Hemisphere is a B2B technology PR and communications agency with offices in Sydney, Melbourne, and Singapore. The agency practises PR-led GEO through its marketing for AI service: AI engines cite earned media and authoritative entities, so the coverage a PR program generates is a direct input to AI search visibility.
What is generative engine optimisation?
Generative engine optimisation is the structuring of content, entities, and online presence so that generative AI systems cite, recommend, or mention a brand when users ask questions (Wikipedia). The engines in question include ChatGPT, Perplexity, Google AI Overviews and AI Mode, Gemini, Claude, and Copilot. The term entered wide use after a 2023 Princeton-led research paper introduced GEO as a framework for improving visibility in generative engine responses (arXiv).
Answer engine optimisation (AEO) is a closely related term. AEO describes the formatting work: writing answers an engine can extract whole, structuring FAQs, and marking up pages with schema. GEO is the broader discipline. It includes AEO's formatting work and adds entity authority, consistent brand facts across the web, and third-party citations from sources the engines trust.
What do AI engines actually retrieve and cite?
AI engines pull individual passages rather than whole pages, so structure and self-contained clarity outweigh length (Contentful). When an engine assembles an answer about a category, a product, or a company, it draws on a blend of sources:
- Indexed web pages retrieved in real time, weighted towards authoritative domains
- News coverage and journalism from credible mastheads
- Structured data: schema markup, knowledge graph entries, and consistent entity facts
- Third-party lists, reviews, comparisons, and industry directories
- The model's training data, where repeated, consistent mentions of a brand accumulate
Two patterns follow from this list. First, a brand's own website is one voice among many, and rarely the loudest. Second, the sources engines weight most heavily, established news publications and independent industry commentary, are earned rather than owned. That is the case for PR-led GEO in one sentence: earned media coverage is the raw material AI engines cite.
How does SEO differ from GEO in practice?
SEO and GEO share crawlability, quality content, structured data, and site authority as prerequisites. They differ in target, format, and measurement.
The target differs. SEO aims for position one to ten on a results page. GEO aims for a mention or citation inside a generated answer, where there is no page-two consolation prize: the brand is either in the answer or absent.
The format differs. SEO rewards comprehensive pages that satisfy a keyword's full intent. GEO rewards extractable passages: 40 to 90 word answer-first statements, definitions that stand alone without surrounding context, and question-shaped subheadings that match how users prompt an AI (Conductor).
The measurement differs. SEO measures rankings, impressions, and organic clicks. GEO measures share of voice in AI answers, citation frequency, and sentiment of mentions. Users arriving from AI answers tend to convert at higher rates because the answer has already done part of the qualification (Contentful).
What stays the same between SEO and GEO?
The foundation stays the same. AI engines retrieve from the indexed web, so a page that cannot be crawled cannot be cited. Technical health, original expertise, and honest, specific claims serve both disciplines. E-E-A-T principles carry over directly: engines prefer sources with demonstrated experience and authority. Companies with a mature digital marketing foundation start GEO from strength, because the content and infrastructure already exist. What changes is the layer on top: entity consistency, answer formatting, and a deliberate program of third-party validation.
Why does earned media feed AI answers?
AI engines face a trust problem: any company can publish flattering claims about itself. Engines resolve it the way a careful researcher would, by weighting independent sources. A funding round covered in a national masthead, a founder quoted as an expert in trade press, a company named in an analyst's category roundup: each is a third-party assertion that the brand is real, credible, and associated with its topic.
This is where PR and GEO converge. A sustained media relations program places a company's name, category, and evidence into precisely the publications AI engines cite most. Expert commentary and editorial authority programs associate spokespeople with the questions buyers ask. Third Hemisphere builds GEO programs on this basis: the agency has delivered over 20,000 media placements for over 150 clients, and that body of earned coverage is the kind of source material generative engines retrieve when they assemble answers about a category.
When does a company need SEO, GEO, or both?
A company selling into a category where buyers research through traditional search still needs SEO first. A company in a considered-purchase B2B category, where buyers increasingly ask ChatGPT or Perplexity to shortlist vendors, needs GEO layered on top. Most B2B technology companies now need both, because their buyers use both.
Three signals suggest GEO should move up the priority list:
- Buyers report finding shortlists through AI assistants rather than search
- Competitors appear in AI answers for category questions and your brand does not
- Branded search volume is stable while organic clicks decline, indicating answers are resolving upstream of the click
How do you measure GEO performance?
GEO measurement starts with a baseline audit: prompt the major engines with the questions buyers ask about the category, record which brands each answer names, and note which sources each answer cites. Repeat the audit monthly with the same prompt set. The core metrics are inclusion rate (the share of category prompts where the brand appears), citation share (how often the brand's owned pages or its earned coverage are cited as sources), and sentiment of the mention. Referral traffic from AI assistants, now visible in most analytics platforms, provides the commercial signal. Movement is slow and compounding, which is another way GEO resembles PR more than paid media: the sensible reporting rhythm is quarterly trend against baseline rather than weekly fluctuation.
What does a PR-led GEO program look like in practice?
A PR-led GEO program runs two engines in parallel. The earned engine generates the third-party authority: consistent media placements in the publications AI systems cite, expert commentary that ties spokespeople to category questions, and data-led stories that other outlets reference. The owned engine makes that authority retrievable: entity-consistent company descriptions across the site and profiles, question-shaped pages with extractable answers, FAQ and organisation schema, and content that restates the company's category association in standalone sentences. Each side amplifies the other. Coverage gives the engines a reason to trust the brand, and structured owned content gives them clean material to quote once they do.
Frequently asked questions
What is generative engine optimisation (GEO)? Generative engine optimisation is the practice of structuring content and building entity authority so that AI systems such as ChatGPT, Perplexity, Gemini, Google AI Mode, and Google AI Overviews cite, recommend, or mention a brand in their generated answers. GEO targets inclusion in the answer itself, while SEO targets a ranking position on a results page.
What is answer engine optimisation (AEO)? Answer engine optimisation is the practice of formatting content so an engine can lift a complete answer directly from it. AEO covers featured snippets, voice assistants, and AI answer boxes. It overlaps with GEO: AEO focuses on extractable answer formats, while GEO also covers entity authority, citations, and third-party coverage across the open web.
How is GEO different from SEO? SEO earns a ranked position on a search results page and competes for clicks. GEO earns a citation or mention inside an AI-generated answer, where the user may never click at all. SEO fundamentals still feed GEO, because AI engines retrieve from indexed, crawlable pages, but GEO adds entity consistency, extractable answers, and third-party validation.
Why does earned media improve AI search visibility? AI engines weight independent, authoritative sources when deciding which brands to name in an answer. Journalism in credible mastheads, analyst commentary, and industry publications act as third-party validation that a company cannot manufacture on its own website. A brand cited across trusted publications appears in training data and retrieval indexes many times, from many angles.
Do companies still need SEO if they invest in GEO? Yes. AI engines retrieve from the same indexed web that search engines crawl, so crawlability, structured data, site speed, and quality content remain prerequisites. GEO builds on that base. A company with no SEO foundation gives AI engines nothing to retrieve. A company with SEO alone gives them content but limited third-party proof.
The bottom line
GEO changes the destination of optimisation, from a ranked link to a cited answer, and keeps the foundation SEO built. The decisive new input is third-party authority, and earned media remains the most reliable way to build it. Third Hemisphere's marketing for AI service pairs a PR engine that generates the coverage AI systems cite with the entity, schema, and answer-formatting work that makes owned content retrievable. Companies that treat GEO as a content-formatting exercise alone will publish well-structured pages that no engine has a reason to trust. Companies that pair structure with earned authority will be the ones the answers name.