Most of the work is the same
Fast pages, clean crawlable URLs, semantic structure, accurate metadata, and credible sources linking to you serve both disciplines identically. Anyone claiming AIEO is an entirely new practice is selling a rebrand.
Difference 1: the unit is a passage, not a page
Search ranks documents; models retrieve fragments. That single change is why structuring so each paragraph stands alone matters far more than it used to, and why your best essay may be invisible while a plain FAQ answer is quoted.
Difference 2: there is no position to hold
You cannot be third in an answer. Either you are part of it or you aren’t, which makes the metric binary per prompt and forces appearance rate over a fixed prompt set in place of rank tracking.
SEO asked where you rank. AIEO asks whether you’re in the answer at all, and how you’re described in it.
Difference 3: description matters as much as presence
Search never characterised you; it just listed you. Models summarise you in a sentence, which makes being described accurately a discipline with no real predecessor.
Difference 4: entity clarity beats keyword coverage
Matching phrases mattered when retrieval was lexical. Reasoning over entities means consistent naming and explicit relationships do work that keyword density used to.
What this means for budget
Keep doing technical and content fundamentals — they serve both. Add measurement of appearance and description, restructure your key pages for passage-level retrieval, and fix your entity basics. That is the genuine incremental work.