Which Sources Do AI Assistants Cite?
This is an ongoing study, not a finished one. We're publishing the methodology now and will publish findings when the sample is large enough to support conclusions. We're deliberately not putting an invented headline statistic on this page — a precise-sounding number we haven't actually measured would undermine the entire reason we publish research at all.
What we're measuring
Across the US, UK, Canadian and Australian markets, for a fixed set of commercial and informational prompts in the marketing-services category: - Which domains are cited by ChatGPT, Perplexity and Google AI Overviews - Whether cited sources skew toward established publishers, vendor sites, or community content - Whether the same prompt returns consistent sources across repeat queries - Whether market (US vs UK vs CA vs AU) changes which sources are surfaced
Why the market variable matters
AI answers appear to be geographically personalised to some degree, which means a business optimising for citation needs to know whether it's being cited in its own market or only elsewhere. This is under-examined publicly and is the part of the study we think adds most.
What we can say now
From the prompt testing we've run so far, the consistent qualitative observation is that pages structured with a direct answer near the top, clear definitions, and comparison tables are cited more often than equivalent-quality content written in continuous prose. That aligns with what's broadly reported elsewhere, and it's the basis of the structural recommendations in our GEO guide.
We're not attaching a percentage to that yet, because we don't have one we'd stand behind.
Methodology limitations we'll state upfront
- [+]Single vertical (marketing services), which limits generalisability
- [+]AI platforms change frequently, so findings have a short shelf life
- [+]Prompt phrasing materially affects results, so results are sensitive to test design
Read our GEO guide →
Written technical findings by senior strategists. Published transparent pricing.