Currently inaccessible in Europe, AI Overviews has begun to shake up web page results across the Atlantic. But to what extent?
At the end of 2023, Google unveiled SGE, a new search experience designed to present AI insights in response to user queries. Renamed AI Overviews and expanded to over 100 countries outside the EU, this new feature has begun to impact page results. But to what extent and for what types of content? Terakeet Engineering, a company specializing in digital marketing, is attempting to answer these questions through a study published on February 24, 2025. Here are its key findings.
Methodology: Application of causal inference
Terakeet Engineering compared the number of clicks on web pages across three types of exposure to AI Overviews (AIO), using the number of clicks as a proxy for web traffic:
- Web pages that appear in SERPs without AIO.
- Web pages that appear in a SERP with an AIO and are mentioned in that AIO.
- Web pages that appear in a SERP with an AIO, but are not mentioned in that AIO.
Furthermore, the study uses a causal inference approach to identify the true causes of traffic variations, while avoiding bias. This approach allows for the demonstration of causality, rather than simply establishing a correlation. In this study, it is used to determine whether the presence of AIOs actually influences web traffic. The challenge is thus to isolate the true effects of AIOs by controlling for confounding variables, which could distort the results. Two confounding variables were identified:
- The position in the SERP.
- The search intent (informational, transactional, navigational or commercial).
To neutralize the effect of these confounding variables, the study segments the data into homogeneous blocks.
AI Overviews: What impact on page traffic?
Pages without AIO vs. Pages included in an AIO
Here, the study compares the traffic of pages when they are included in an AI preview and when they appear on a SERP without AIO.
Informational pages in the top three positions of the SERP see their traffic reduced by the appearance of AI Overviews. On the other hand, for transactional pages ranked in the top three of the SERP, being included in an AIO seems slightly positive. But in both cases, the impact is not significant.
The effect is much more pronounced for lower-ranking pages (positions 3 to 10): informational pages included in an AIO get twice as many clicks, while transactional pages benefit even more, with a 3.6-fold increase in traffic. This suggests that the AIO redistributes traffic to lower-ranking results when it is present on the SERP.
Pages without AIO vs. Pages excluded from an AIO
Here, the study compares the traffic of pages when they are not included in an AI preview and when they appear on a SERP without AIO.
For the top 3 informational and transactional pages, excluding them from the preview results in a sharp drop in traffic, with 2 and 2.3 times fewer clicks, respectively, than when they are included. AIO therefore appears to be diverting a significant portion of traffic away from the pages it does not highlight.
On the other hand, the trend is reversed for lower-ranking pages: those excluded from the AIO paradoxically obtain more traffic than those appearing on a SERP without AIO, in particular transactional pages, whose clicks are multiplied by three.
Pages included in an AIO vs. Pages excluded from an AIO
Here, Terakeet Engineering looks at SERPs displaying AI Overviews, directly comparing pages that are included in the overview and those that are not.
For top-3 informational pages, being included in an AIO results in a slight traffic gain (1.5 times more clicks). However, for high-ranking transactional pages, inclusion has a greater effect, with traffic 3.2 times higher than that of excluded pages. For lower-ranking pages, the effect of inclusion is much more moderate, with a negligible difference between included and excluded pages.
Who benefits from AI Overviews?
What general conclusions can be drawn from these results? For Terakeet Engineering, the study highlights the following lessons:
- Inclusion in an AIO is beneficial for a page, regardless of its type (informational or transactional).
- For informational queries, the presence of an AIO reduces traffic to high-ranking pages, whether they are included or not. Conversely, lower-ranking pages see their traffic increase thanks to the AIO.
- For transactional queries, being included in an AIO increases traffic, across all positions in the SERP.
- High-ranking and lower-ranking pages respond differently to the previews, with their traffic changing differently based on their exposure to these automated responses.
