AEO and SEO are not replacements for each other. They are layers. SEO got your URL onto the first page of Google. AEO gets your brand into the sentence ChatGPT writes when a buyer skips Google and asks the assistant directly. Both still matter. They use overlapping inputs (your pages, your authority, your citations) but they reward different outcomes.
What stays the same
High-quality content, clean technical execution, and authoritative backlinks help in both worlds. The crawlable, fact-rich pages that rank in Google are also the pages LLMs prefer to cite. If you have invested in SEO, you have invested in AEO too, just along one axis.
What is different
Three things. First, the metric: SEO measures position on a list, AEO measures whether you are inside a sentence. Second, the variability: SEO results are deterministic, AEO results are stochastic. Third, the optimization surface: SEO is mostly about your site and your backlinks, AEO is also about the third-party comparison articles, the Reddit threads, and the academic citations the model retrieves alongside your site.
Where to start if you do both
Audit your existing top SEO pages and ask: do they have the kind of evidence (numbers, direct quotes, structured stats, citations) that LLMs prefer to lean on? Most pages that rank well still read like marketing copy. The fastest AEO wins are usually rewrites of the highest-traffic pages you already own, adding the kind of substance the model needs to confidently quote you.