When someone asks ChatGPT which software tool to use, or asks Perplexity which brand to trust, or asks Gemini which startup is worth evaluating — is your company in the answer? Do you even know? That is the exact problem Profound was founded to solve. On September 15 2026, the New York-based AI marketing startup raised $180 million in a Series D at a $1.8 billion valuation, led by Sequoia Capital and Kleiner Perkins, with Lightspeed Venture Partners, Khosla Ventures, Saga Ventures, Evantic, and South Park Commons also joining. Follow every US startup funding story at BestStartup US.
What Profound Does — AEO GEO and the New Search Marketing Stack
Profound is an analytics platform that helps brands track and improve how they appear in AI-generated search results across ChatGPT, Perplexity, Gemini, and Google AI Overviews. For thirty years marketing teams measured search performance through Google rankings and page-one SEO. AI search has changed the output entirely — instead of a ranked list of links, users now receive a written answer composed by an AI model. The brands that appear in those answers are not necessarily the brands that rank first on Google. They are brands that AI models have learned to trust.
The category that Profound operates in has two names used interchangeably. Answer Engine Optimisation — AEO — is the discipline of structuring content so AI models cite it directly in answers. Generative Engine Optimisation — GEO — covers the same territory from a content and authority signal perspective. Profound measures both simultaneously, showing brands how often they are mentioned, in what context, and against which competitors — then provides AI agents that suggest and in some cases make automated changes to improve that visibility when it drops. Read every US AI startup story at BestStartup US.
Why This Round Is Historically Significant
The $180 million Series D nearly doubled Profound’s February 2026 valuation — from approximately $960 million to $1.8 billion — in seven months. The previous $96 million Series C had already made it a unicorn. Sequoia Capital and Kleiner Perkins jointly led the Series D investment, joined by Lightspeed Venture Partners, Khosla Ventures, Saga Ventures, Evantic, and South Park Commons. Both Sequoia and Kleiner Perkins have now led three of Profound’s four rounds — a level of institutional commitment that signals category conviction rather than financial opportunism.
Profound has also built AI agents of its own, which monitor brand mentions and can suggest, and in some cases make, changes when a company’s visibility drops. That product extension — from analytics to autonomous optimisation — is the commercial expansion that justifies the valuation step-up. A platform that measures visibility is a dashboard. A platform that autonomously improves visibility is a recurring-revenue workflow tool with dramatically higher switching costs. Follow AI startup funding at BestStartup US.
The G2 Partnership and Enterprise Distribution
G2 announced a new partnership with Profound that will equip B2B software companies to shape their answer engine optimization and AI search marketing strategies. G2 is the most cited B2B software source across LLMs and ranks 4th among the top 10 cited sources on ChatGPT and 9th on Perplexity. The distribution partnership gives Profound access to thousands of B2B software companies that already trust G2 as their review and visibility platform — and who now need to understand their visibility in AI search alongside their traditional review presence.
What AEO and GEO Mean for Every US Marketing Team
The Profound round is a signal to every marketing team in the United States that AI search visibility is no longer an emerging concern. It is a venture-backed category attracting Sequoia and Kleiner Perkins capital at $1.8 billion valuations. The teams that begin measuring and optimising their AI search presence in 2026 will have a compounding advantage over those who wait until the category is fully mature and competitive. Also read: Harvey $550M legal AI and the biggest US startup funding week of September 2026. Follow every US startup story at BestStartup US.
Key Takeaways
Profound raised $180 million Series D at a $1.8 billion valuation on September 15 2026. Sequoia Capital and Kleiner Perkins co-led the round — their third co-lead together in Profound. Lightspeed Venture Partners, Khosla Ventures, Saga Ventures, Evantic, and South Park Commons participated. Founded in 2024 by James Cadwallader and Dylan Babbs. Platform tracks brand visibility across ChatGPT, Gemini, Perplexity, and Google AI Overviews. AI agents now autonomously monitor and improve brand visibility when it drops. G2 partnership provides B2B software distribution. Total raised exceeds $335 million since 2024. US startups raised more than $400 billion in H1 2026.
Frequently Asked Questions
What is Profound and what does it do?
Profound is a New York-based AI marketing platform founded in 2024 that helps brands measure and optimise their visibility in AI-generated search answers across ChatGPT, Gemini, Perplexity, and Google AI Overviews. It raised $180 million Series D at a $1.8 billion valuation on September 15 2026.
What is AEO — Answer Engine Optimisation?
AEO stands for Answer Engine Optimisation — the practice of structuring brand content and authority signals so AI models cite a brand accurately and prominently when generating answers about a category or decision. It is the AI search equivalent of SEO for traditional search engines.
What is GEO — Generative Engine Optimisation?
GEO stands for Generative Engine Optimisation — the discipline of optimising brand presence specifically for generative AI outputs from ChatGPT, Gemini, Claude, Perplexity, and similar models. It covers training data sources, real-time web retrieval signals, and the authority indicators that determine whether a brand is cited in AI-generated answers.
Why did Sequoia and Kleiner Perkins lead the Profound Series D?
Sequoia and Kleiner Perkins believe AI search visibility is a new category requiring purpose-built infrastructure — not a feature existing analytics platforms will add. They have now co-led three of Profound’s four rounds, signalling conviction that AEO and GEO represent a durable, category-defining commercial opportunity.
Where can I follow US startup funding news?
Follow every US startup funding round, AI company news, and investment trend at BestStartup US — updated every week.
