Koah Raises $20.5M to Build "AdSense for AI"

$20.5M Series A, Led by Theory Ventures

Koah, which enables contextual advertising natively inside generative AI, has closed a $20.5 million Series A led by Theory Ventures. Tomasz Tunguz, Theory's Founder and General Partner and a Google AdSense alum, joins Koah's board as part of the round. The raise builds on the company's $5 million seed from September 2025 and brings total funding to more than $26 million.

What Koah Actually Does

Koah bills itself as the "AdSense for AI." Its lightweight SDK installs in minutes and lets AI apps monetize high-intent conversations through native, contextual ads, without breaking the chat experience. Co-Founder and CEO Nic Baird frames the bet plainly: subscriptions alone don't scale against high inference costs, and legacy ad formats erode trust in AI experiences. Koah is trying to build the monetization layer that sits between the two.

The Traction Behind the Round

Over the past 12 months, Koah's ecosystem has scaled to more than 2 million monthly active users engaging with conversational AI three times a day. The company has served over 35 million native ad impressions across 175 million queries, and already powers monetization inside AI apps including Liner, Viro, and Sup AI. Liner's CEO Luke Kim, whose AI search product serves more than 10 million students, academics, and researchers, says users are researching and forming brand preferences directly inside the tool, and Koah lets that happen without compromising trust.

Why Investors Are Paying Attention

Tunguz's framing is that AI apps represent a new interface layer for the internet, and that layer needs monetization infrastructure built for it, not bolted on. For advertisers, Koah offers a new channel with unusually rich intent signals, reaching people in the exact moment they're comparing options and making decisions. The new capital goes toward engineering hires and go-to-market expansion, alongside new analytics tools and ad formats built specifically for conversational environments.

What It Means for Marketing

This round is a marker for where AI monetization is heading in 2026: not bigger subscription tiers, but an entirely new ad layer built for conversational surfaces. As more discovery and comparison shopping moves inside chat and AI search, the channel that can reach users mid-conversation, without feeling like an ad, becomes a genuinely new line in the media plan. For marketers still thinking about AI purely as a content or research tool, Koah's raise is a signal that it's also quietly becoming a distribution channel.