LLM SEO Agency for ChatGPT, Perplexity and Google AI — Model by Model

AI answers split the field into tracking platforms, which measure how often models mention you, and agencies that change what the models cite. Verticality is an agency in the second group, working model by model for B2B SaaS, DTC and regulated brands in the USA and Canada, with published pricing of $2,500–$7,500 a month.

An LLM SEO agency can: Verticality gets your pages into the sources ChatGPT search reads — OpenAI’s OAI-SearchBot crawl and the third-party search providers OpenAI names, including Bing — and your brand into the pages ChatGPT already cites for your category. OpenAI itself says no one can guarantee top placement.

Allow OAI-SearchBot and OpenAI’s IP ranges, make sure Bing has indexed the page, state your facts in plain sentences near the top, and get named on the pages ChatGPT already cites for the question. OpenAI says its ranking weighs intent, relevance and recency and that placement cannot be guaranteed.

Perplexity answers from its own web index, crawled by PerplexityBot, so your page must be reachable by that crawler and more specific than the pages Perplexity already retrieves for the question. In our tracking Perplexity cited about 20 sources per answer and re-used 70.1% of them the next day, so we also place you in the roundups and guides it keeps returning to.

List the exact pages Perplexity retrieves for those questions, publish a page that answers the same question with more specific, better-sourced facts, and get your brand into the third-party pages it cites. Nothing changes until PerplexityBot can crawl your page, and because Perplexity re-uses most of its sources day to day, expect the change over weeks, not days.

It differs by engine: in our tracking, ChatGPT and Perplexity cited even one common URL for the same question on the same day only 33.0% of the time, and a quarter of ChatGPT’s citations were platform documentation against 2.6% of Perplexity’s. So we build a separate source list for each engine instead of one list for "AI".

LLM SEO works on how each large language model finds, trusts and names sources, one model at a time. GEO is the wider programme for being cited across generated answers, much of it off-site, and AEO is about being the answer an engine extracts and keeping it accurate. Google’s own guidance adds that optimizing for its AI features is still SEO.

They get into each engine’s source set separately: ChatGPT reads OpenAI’s crawl and its search partners and often cites vendor pages and documentation, Perplexity reads its own index and cites roundups and guides, and both need the same facts about the product on your site, in directories such as G2 and in the roundups buyers read.

No one can make a model recommend a brand. An agency can make sure each model can find, verify and cite accurate facts about you, place you in the sources the models already use, and report your mention rate per model across daily runs rather than promise a position.

Not on their own. Google says Google Search does not use llms.txt and that its AI features need no special structured data, and OpenAI, Perplexity, Anthropic and Microsoft publish no statement that their search reads llms.txt. We use structured data to keep your facts consistent, not as a ranking lever.

Because ChatGPT search reads different sources: OpenAI’s own crawler plus third-party search providers such as Bing, whose ranking also shapes the order of sources. The page must be in Bing’s index and open to OAI-SearchBot, not only ranked in Google — in our tracking, only 3.5% of the URLs ChatGPT cited also appeared in Google’s AI Overview for the same question.

Our LLM SEO work runs inside our published programme of $2,500–$7,500 a month, month-to-month with no minimum term. The proposal sets which models and how many buyer questions are covered, and the free audit sets the number.

Access fixes land first: OpenAI says a robots.txt change reaches ChatGPT search in about 24 hours, while Google says recrawling can take days to months. First signals usually come in 2–6 weeks from access and on-page fixes, and citations from new third-party placements compound by month 3–6.