What is AEO? What is GEO? What is AI Search Optimization?

GEO (Generative Engine Optimization), AEO (AI Engine Optimization), and AI Search Optimization are all terms used interchangeably to describe the practice of optimizing your online presence and content to improve how your brand appears in AI-generated responses. These practices focus specifically on influencing how generative AI models perceive, understand, and recommend your brand.

What is a citation in AI search?

In the context of AI-generated responses, a citation is a reference to a source that the AI model used to generate information in its response. Citations typically appear as links, footnotes, or inline references that direct users to the original content. Citations are important for understanding and optimizing your brand's AI visibility because they show which content AI models are using to form their knowledge about your industry, brand, or competitors.

LLM stands for Large Language Model - a type of artificial intelligence trained on massive amounts of text data to understand and generate human-like language. LLMs are trained by reading billions of words from the internet, books, articles, and other text sources. Through this training, they learn patterns in language, facts about the world, and how to generate coherent, contextually relevant responses.

What is the difference between GEO and SEO?

While GEO (Generative Engine Optimization) and SEO (Search Engine Optimization) share similar goals - improving brand visibility - they optimize for fundamentally different systems and user experiences. SEO optimizes for search engine rankings; GEO optimizes for AI model knowledge and recommendations. SEO focuses on keywords and backlinks; GEO focuses on comprehensive content that educates AI models. SEO results appear as ranked links; GEO results appear as narrative recommendations within AI responses.

Does ChatGPT give the same answer to everyone?

No, ChatGPT does not give identical answers to everyone. AI models are predictive by nature, which means responses vary. This variability is why Evertune tests millions of prompts - to understand how AI models respond at scale and identify consistent patterns in brand recommendations.

ChatGPT Shows an Ad in 1 in 8 Responses

ChatGPT displays an ad in about 13% of responses, meaning on average a user sees an ad once in every eight responses, our review of more than 400,000 ChatGPT responses found.

OpenAI began testing ads in ChatGPT in February and launched its self-serve advertising platform on May 5. Ads are currently displayed to users in the US, UK, Australia, New Zealand, and Canada on Free and Go plans, excluding users under 18 years old.

We used the Evertune AI marketing platform to review 12 categories of prompts and found that the ad trigger rate varied from a low of 6.7% for prompts about games to a high of 17.8% for prompts about home and garden.

ChatGPT Ad Trigger Rate by Category

ChatGPT Response Rate with Ads by Category

Share of ChatGPT responses that included an ad, by content category

More than 1,000 brands advertised within our response sample. The most prolific advertisers across all categories were:

BestMoney (7.6% of ads)
Autotrader (5.9% of ads)
Home Depot (5% of ads)
Expedia (3.7% of ads)
MANSCAPED (3.5% of ads)

Within several categories, the biggest advertisers enjoy a quite comfortable lead over the second-biggest advertiser. BestMoney, for example, had five times as many ads appear in responses to finance prompts as Chime, the category’s second largest advertiser.

ChatGPT Ad Category Leaders

ChatGPT Ad Proliferation Leaders by Category

Number of times an ad from each brand appeared in a ChatGPT response

No. 1 Advertiser

No. 2 Advertiser

Given how differently users prompt and large language models’ probabilistic methods of responding, advertisers cannot simply target a set of keywords as they do in traditional web search. Instead, advertisers utilize context hints - short, plain-language descriptions of the buyer moment in which brands are relevant and want their ads to appear.

These are early days for ChatGPT ads and for brands’ advertising strategies. Ads’ proliferation could accelerate, as ChatGPT did with shopping experiences, or OpenAI could maintain the current rate for the sake of user experience.

Brands are not likely to enjoy sizable advertising leads for long as more and more brands dip their toes into the pool of AI advertising. ChatGPT, too, will face competition for ad dollars as competitors like Google roll out ads in Google AI Mode and in Google AI Overview. Evertune will continue to report on changes in AI advertising.

Methodology

At Evertune Research, we track hundreds of brands across 250 categories. For this analysis, we ran more than 401,000 prompts on ChatGPT from May 21 to June 8 across 12 categories.

Evertune is the AI marketing platform for brands that want to own the AI customer journey. Evertune analyzes prompt responses at scale across all major LLMs, ChatGPT, Claude, Gemini, AI Overviews and more, to deliver statistically significant visibility data, then closes the loop with tools to act on it: website optimization, data-driven content creation, most influential sources, and paid activation through affiliate and programmatic AI retargeting partners. Where most tools tell you where you stand, Evertune tells you what to do about it. Founded by early executives of The Trade Desk and backed by $20M from leading investors.

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