Google’s October 28 Ads Decoded episode was billed as a look at how AI is changing search behaviour. Shivani Mohan, Google’s Search VP of Data Science and User Experience Research, told host Ginny Marvin that query length “has increased 3x,” and that “one in every six searches is multimodal.”
Those numbers need boundaries
The episode did not say what the 3x is measured against, which market it covers, or what time period it describes. In May, Google published similar statistics with tighter wording. The average AI Mode query was about three times the length of a traditional search query. More than one in six AI Mode searches in the United States were multimodal, and follow-up queries in AI Mode grew by more than 40% a month on average in the US.
On the October podcast, both figures sounded like they covered all of Google Search. That distinction matters. AI Mode is one surface users choose to enter; it is not the whole search corpus.
Why ad matching is changing
The most actionable claim came from Marvin. Ads in AI Mode and AI Overviews are matched to both the query and the content of the AI response. In practice, your ad is not evaluated only against the words someone typed. Google is also using the full AI answer as context.
Mohan said search is moving up the funnel. People are asking more brainstorming and discovery questions, not just final purchase queries. Marvin told advertisers to look beyond last-click actions and think about discovery, research, awareness and consideration.
What to change before the next planning cycle
- Feed Merchant Center’s six optional conversational product fields instead of leaving product data minimal.
- Replace generic product blurbs and high-level corporate copy with specific, fact-led answers.
- Treat AI search as an upper-funnel discovery surface, not only a bottom-funnel action channel.
- Build comparison content, how-to video and specialized detail that matches longer questions.
Mohan said users still want authoritative and authentic human voices. They may start with an AI summary and then dig into podcasts, YouTube reviews or niche sources. That is a content signal: generic pages are losing ground to specific, detailed material.
One caution: the episode gave no click-through, conversion or cost data for AI search ads. Independent research has pointed to fewer clicks from AI Overviews: a randomized study found AI Overviews cut outbound organic clicks by 39.8% among a sample of Chrome users, and Ahrefs reported lower click-through rates where AI Overviews appear. Google itself says AI surfaces send billions of clicks weekly, but no comparison period was offered.
Treat the 3x figure as directional, and test before you shift budgets wholesale.
Source: PPC Land
