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llms.txt GeneratorDoes raw domain count matter more than repeat-cited authority?
Raw domain count and repeat citation count answer different questions. The index shows 725,777 domains and a 5.82% share for the top three, but it does not measure “authority” as a causal variable.
The key numbers.
- Unique domains
- Distinct normalized domains in the current brand snapshots.
- 725,777
- Unique cited URLs
- 3,687,821 distinct cited URLs in the current snapshot.
- 3.69M
- Top three domain share
- YouTube, google.com, and Reddit together account for 5.82%.
- 5.82%
Use domain breadth for coverage and repeat appearances for concentration. Do not turn either into a causal ranking factor without a separate test.
The evidence.
Source
AI Citation Index
| Measure | Result |
|---|---|
| Unique domains Distinct normalized domains in the current brand snapshots. | 725,777 |
| Unique cited URLs 3,687,821 distinct cited URLs in the current snapshot. | 3.69M |
| Top three domain share YouTube, google.com, and Reddit together account for 5.82%. | 5.82% |
Population and method
Built from 80,769,585 citation appearances across 725,777 unique domains in the latest valid snapshot for 1,928 tracked brands, observed from October 3, 2025 to October 14, 2026.
Where the evidence stops
The index is a changing panel of tracked brands and prompts, not a random sample of all AI responses.
Domain share is observational. It does not establish causal influence or reveal the full retrieval set.
The hand-maintained source taxonomy is partial: 88.40% of citation appearances remain in “other”.
Model attribution, response-level citation denominators, geography, raw prompts, and raw responses are not retained in the public aggregate.
What to do with this
- Audit the domains that already dominate your category and decide which ones are realistic citation targets.
- Build source-worthy pages for the query shapes where AI is already citing third parties.
- Treat reference, review, and social sources as part of your AI visibility surface, not as noise.
This answer matters because it turns a study finding into an operating rule teams can use when they decide what to publish, refresh, or measure next.
Questions about this answer.
Cite this answer.
Source study: Citation Sources“Raw domain count and repeat citation count answer different questions. The index shows 725,777 domains and a 5.82% share for the top three, but it does not measure “authority” as a causal variable.”
Mack Grenfell · Does raw domain count matter more than repeat-cited authority?
AI Citation Index · Trakkr Research · Updated 14 October 2026