How Generative AI Disrupts Search: An Empirical Study of Google Search, Gemini, and AI Overviews
Riley Grossman, Songjiang Liu, Michael K. Chen, Mike Smith, Cristian Borcea, Yi Chen
If you run a content site, generative search is already reshaping half your potential traffic. Blocking AI crawlers reduces AIO visibility. Google-owned properties gain distribution advantage. Plan for a world where institutional authority matters less.
Generative AI is replacing traditional search results, but nobody knows how it changes which sources get traffic or whether it retrieves the same information.
Method: Analyzed 11,500 real-user queries across Google Search, AI Overviews (AIO), and Gemini. AIOs appear for 51.5% of queries, displayed above organic results. Retrieved sources show <0.2 Jaccard similarity between systems. Traditional Google significantly favors institutional sites (.gov, .edu); generative search significantly favors Google-owned content. Websites blocking Google's AI crawler are significantly less likely to appear in AIOs despite content availability.
Caveats: Single snapshot study. Doesn't track how these patterns evolve as Google adjusts AIO algorithms or revenue models.
Reflections: Do websites that allow AI crawling see measurable traffic increases, or does AIO cannibalize clicks regardless? · How do generative engine optimization techniques perform when sources differ so dramatically across systems? · What revenue framework could sustain publishers when generative search surfaces their content without click-through?