Generative engine optimization — GEO — is the work of getting a brand named inside the answer a generative engine produces, rather than inside the list of links beneath it. The engines in question are ChatGPT, Google’s AI Overviews and AI Mode, Perplexity, Copilot and Gemini. Each one composes an answer from retrieved sources, so the question stops being where do we rank and becomes which sources does it read, and do they mention us.
That difference is the whole discipline. A traditional ranking is a position you hold. A generative answer is a paragraph someone else wrote about your category, and your name is either in it or it is not. There is no page two to be consoled by.
Three or four brands get named in a typical answer. Position eight on a SERP still earns some clicks; not being named earns nothing, and the buyer never learns you existed.
A model treats your own marketing copy as a weak claim and a trade publication as evidence. This inverts the usual agency instinct to fix the website first and worry about coverage later.
A clean, self-contained statement of fact is liftable. The same fact spread over a page of narrative is not. Long-form still helps discovery; it is the sentence-level clarity that gets quoted.
Ask the same question twice and the answer may differ. Anything measured from a single run is anecdote. GEO measurement has to be a repeated prompt set read as a trend.
Retrieval favors sources that agree with each other and were updated recently. A decade-old authoritative page can lose to three recent ones that say the same thing.