User location changes sources cited by generative search engines
Location, Location, Generation: Where You Ask Matters for Generative Engine Optimization
Information RetrievalComputation and LanguageMachine LearningSocial and Information Networks
Summary
Generative search engines create answers by citing sources, but which sources they show depends on where you are. The authors asked ChatGPT and Gemini questions from different places and found ChatGPT changes its sources based on the declared city, while Gemini uses the network location to pick sources. This means the businesses and information you see can vary just because of your location. The authors show that tracking these differences is important to understand how these engines work and which sources get visibility.
What this means in practice
- •For digital marketing teams: Monitor how user locations influence which sources and businesses generative search engines recommend to optimize local visibility in automated answers.
- •For search engine developers: Design generative search systems that control input location channels to manage local relevance and prevent unwanted geographic bias in cited sources.
Authors
Mahe Chen, Nick Koudas
Abstract
Generative search engines answer local and commercial questions with a written answer and a few cited sources. A growing practice of generative engine optimization (GEO) monitors which sources and brands these answers show, typically from a single place. In this paper, we present a controlled audit of how the user's location changes the sources that generative engines cite. We ask 300 questions of ChatGPT with 19 declared locations, and of ChatGPT and Gemini from five network locations, each twice to measure run-to-run noise (31,200 answers). The engines take location from different channels. ChatGPT follows the location an application declares, down to the city: it writes the place into its own searches, and its search backend localizes results even when the queries name no place. It ignores the network. Gemini ignores the declared location and follows the country of the network, changing most of its sources even for questions that do not depend on place. The businesses the answers recommend change with the sources. Thus, visibility in generative search is specific to the user's location, and audits must control both channels.