Domain concentration in AI answers: the top 100 domains take 58% of citations
Across 250,000 citations collected from six engines, the top 100 domains accounted for 58% of all citations and the top 1,000 for 84%. Concentration is materially higher than the classic organic SERP for the same queries, and user-generated platforms — Reddit, Quora, Zhihu, Stack Overflow — took 17% of the total.
- Method
- 250,000 citations sampled from 10,000 prompts across six engines over 30 days
- Sample
- 250,000 citations
Method
Ten thousand prompts across twelve verticals, ten samples each, six engines, thirty days. Every cited URL was normalised to a registrable domain and categorised: brand-owned, publisher, user-generated, retailer, government or academic, and reference (encyclopedias, standards bodies).
Concentration
| Bucket | Share of all citations |
|---|---|
| Top 10 domains | 21% |
| Top 100 domains | 58% |
| Top 1,000 domains | 84% |
| Everything else | 16% |
For the same query set, the classic organic top-10 results spread across roughly 2.4x more distinct domains. AI answers are a narrower funnel, and the narrowing is consistent across engines rather than driven by one outlier.
Category shares
| Category | Share | Direction over 30 days |
|---|---|---|
| Publisher | 29% | Flat |
| Reference | 22% | Up |
| User-generated | 17% | Up |
| Brand-owned | 15% | Down |
| Retailer | 11% | Flat |
| Government / academic | 6% | Up |
Brand-owned pages take a smaller slice than most marketing teams assume. In commercial-intent prompts specifically, brand-owned pages were 15% of citations while third-party reviews, listicles and community threads were 46% combined.
What this changes
Engine differences worth knowing
ChatGPT leaned hardest on user-generated sources (23%). Perplexity was the most publisher-weighted (36%). Baidu ERNIE was the most self-referential of all: 41% of its citations pointed at Baidu-owned properties.
Evidence
Raw answers, per-cell sample sizes, collection dates and parser versions behind every figure here are available to customers on request. We publish the method so the numbers can be checked rather than taken on faith.
See this for your brand
Every figure here comes from the same measurement behind our dashboard and API. Tell us what you want measured and we'll show you where your brand stands.