Similarweb Adds AI Ad Intelligence to Its Platform for ChatGPT and Google AI
"This is the rare moment when a major ad channel is still wide open."
Similarweb announced AI Ads on August 17, the first competitive intelligence dataset tracking advertising placements across ChatGPT, Google AI Mode, and Google AI Overviews.
This is to address a transparency gap that has made AI advertising the only major ad channel without a public visibility mechanism for competitors or advertisers themselves, according to the company.
Similarweb's real user panel data shows that 26% of ChatGPT responses served to Free and Go tier users already carry a sponsored ad.
Nearly 30% of ad-eligible Google AI Mode queries show ads. And over 40% of Google searches now trigger an AI Overview, a surface that frequently includes advertisements alongside the AI-generated answer. The channel is not emerging. It is already running at a meaningful scale with no public transparency infrastructure around it.
"This is the rare moment when a major ad channel is still wide open," said Harel Amir, General Manager and Head of Product for Similarweb Ad Intelligence. "The advertisers who can see what's happening with AI ads now will have a real head start. Until today, nobody could see it at all."
Every other major digital advertising channel has a public transparency layer. Meta built the Ad Library. Google built the Ads Transparency Center. TikTok built the Creative Center.
These tools let advertisers and their competitors see what is running, where it is running, and how it is positioned. ChatGPT, Google AI Mode, and AI Overviews have none of that infrastructure, not for competitors and often not even for the advertiser's own team.
The practical consequence is that advertisers running campaigns on ChatGPT have no visibility into the competitive auction they are participating in. Google advertisers enrolled in broader digital advertising programs cannot verify whether their campaigns are appearing in AI-generated answers at all.
The Similarweb AI Ads dataset fills that gap using data drawn from real user panel conversations, which is the methodological distinction that makes the findings actionable rather than illustrative.
ChatGPT ad placement introduces an additional layer of complexity that traditional advertising intelligence tools were not designed to handle. Unlike keyword-based search advertising where bid price and quality score determine placement, ChatGPT ads only surface when the conversational AI identifies and clarifies purchase intent from the user's messages.
Placement is determined by the combination of ad creative, copy, and landing page rather than keyword targeting, according to the company.
"When we started advertising on ChatGPT, we were flying blind — no visibility into who else was in the auction or what was working," said Jonathan Bar Vardi, Head of Strategy at Natural Intelligence, one of the largest buyers of ChatGPT ads. "Similarweb changed that."
Future releases of the AI Ads dataset will add share of voice, ad categories, and conversational intent metrics.
Key Takeaways
- Similarweb launches AI Ads, tracking ad placements across ChatGPT and Google AI platforms.
- Address transparency gaps in AI advertising, currently lacking public visibility for competitors and advertisers.
- 26% of ChatGPT responses and nearly 30% of Google AI Mode queries already feature ads.
- Advertisers gain a competitive edge by accessing real-time AI ad insights before the market saturates.
- Unlike other platforms, no public transparency tools exist for AI advertising, presenting a unique opportunity.