Brands appear inside ChatGPT answers for a specific set of reasons. The reasons are knowable. They are not random, and they are not the same as the reasons brands appeared in Google's top ten links.
Authority of source matters more than density of keyword. Original reporting beats aggregation. Trusted publications outweigh thin SEO content. Schema and entity clarity drive retrieval. Reddit, Quora, and Wikipedia punch above their weight because the model trusts them. Citation graphs — who is cited by whom, in which trustworthy contexts — shape the model's confidence that a brand belongs in the answer.
Generative Engine Optimization is the discipline of turning those reasons into work. It is not SEO with a new name. The rules are different, the surfaces are different, the measurement is different. A brand can rank well on Google and still be invisible on Perplexity. A brand can be unknown to Google and dominant inside Claude. Each engine has its own retrieval graph and its own taste.
The work that gets a brand into the answer looks like this: original research and reporting that engines cite, schema and structured data the engines can parse, coverage in publications the engines trust, presence in forums the engines also read, Citation Share measurement across all five engines refreshed on a regular cadence, and reputation remediation when the answer is wrong.
Public relations plus digital marketing plus GEO plus research, combined for one objective: be the answer.