Copilot's September 2026 US list is a shopping index. Ahrefs, over 3 million queries: Amazon 16.8% of the top-50 pool, Walmart 12.6%, English Wikipedia 7.6%. A Walmart tracking subdomain is seventh, so Walmart is in the head twice. Reddit is not in the top 50. YouTube is eleventh.
- Amazon plus Walmart plus goto.walmart.com is 32.4% of the top-50 pool, before Target, Etsy, Home Depot, Best Buy, Macy's, and Lowe's.
- Wikipedia is the main reference site, third at 7.6% and 118,076 pages. That is close to its 7.0% on ChatGPT's top-source pool the same month, in a completely different neighbourhood.
- Reddit is outside the published top 50. Profound ranked it 31st on Copilot in November 2025. The direction agrees. The counts are not the same metric.
- Profound's category row puts Copilot at 59% brand and 33% media, the highest media share in that seven-platform table, and 3% social. The sample size was not in the extracted text.
- Mention share cannot be added to a category share. Amazon-plus-Walmart and "59% brand" are the same story told with two denominators. They are not two measurements of one number.
The US list
Ahrefs, "The 50 Most-Cited Websites in Copilot," updated 2 September 2026. Every domain Copilot cited across over 3 million US queries, all topics. Mention share divides by the top 50. Pages cited are distinct URLs. This is the public ranked list. A Profound all-citation top ten for Copilot was not found.
| Rank | Domain | Mention share of the top 50 | Pages cited |
|---|---|---|---|
| 1 | amazon.com | 16.8% | 775,592 |
| 2 | walmart.com | 12.6% | 544,116 |
| 3 | en.wikipedia.org | 7.6% | 118,076 |
| 4 | scienceinsights.org | 3.5% | 55,040 |
| 5 | engineerfix.com | 3.3% | 73,880 |
| 6 | grokipedia.com | 3.1% | 62,702 |
| 7 | goto.walmart.com | 3.0% | 88,672 |
| 8 | target.com | 2.8% | 80,247 |
| 9 | biologyinsights.com | 2.5% | 56,374 |
| 10 | etsy.com | 2.4% | 151,372 |
Ranks 11 to 20: YouTube 1.9%, Home Depot 1.9%, WikiHow 1.8%, Best Buy 1.8%, Kelley Blue Book 1.6%, Edmunds 1.6%, Macy's 1.5%, Lowe's 1.4%, Forbes 1.4%, Merriam-Webster 1.3%. Further down, still inside the top 50: Mayo Clinic 25th at 1.1%, Healthline 30th at 0.9%, LinkedIn 37th at 0.8%, Consumer Reports 35th at 0.8%, Britannica 48th at 0.8%.
The page counts are the tell. Amazon's 775,592 cited pages and Walmart's 544,116 are product URLs, not a handful of evergreen guides. Wikipedia, third on share, has fewer pages than either retailer. Copilot is citing the catalogue.
Why this one is retailers
Set this table next to ChatGPT's September list and the difference is the point of having two pages. Same vendor, same month, same definition of mention share. ChatGPT's head is Reddit, Wikipedia, Consumer Reports, and Forbes. Copilot's head is Amazon and Walmart. A team that "optimises for AI" as one channel will aim at the wrong host on at least one of them.
Profound's January 2026 category table is the class version. Copilot: brand 59%, media 33%, institution 6%, social 3%. ChatGPT: 54%, 25%, 15%, 5%. Copilot's media share is the highest in that table and its social share is among the lowest. "Brand" there means the owned-domain side of the mix, which is where a retailer lives. The sample size was not printed in the extract, so the row stays partial.
Professional queries are a different Copilot, and Profound did not publish it separately. From 15 November 2025 to 15 February 2026, LinkedIn became the number one domain for professional queries across six models, one of them Copilot, on 1.4 million citations. That is not the all-topic list above, where LinkedIn is 37th.
Where Reddit ranks
Profound, 10 November 2025, in a post done with Reddit: Reddit's domain rank was 31 on Copilot, 1 on Perplexity, 2 on ChatGPT, 2 on AI Overviews, 3 on AI Mode, and 2 on Grok. The cross-engine shares in that post are pooled. They are not Copilot-only percentages. The rank is the Copilot fact.
September 2026 is consistent with that rank. Reddit does not appear in the published top 50. Otterly's September social table, on another panel, showed no Reddit citations for Copilot. Two absences still are not a measured zero. They are enough to stop a plan that treats "get on Reddit" as the Copilot tactic.
What this does not prove
It does not say Copilot is Bing, or that Bing's top ten is this list. It does not say the citations were accurate. The Tow Center's March 2025 test found Copilot was the tool that refused more often than it answered, and it did not print an error rate in the prose. Refusal is a behaviour. It is not a domain share.
Bing Webmaster Tools added an AI Performance report in public preview on 10 February 2026, covering Copilot, Bing's AI summaries, and some partner services. A June update added citation share for a grounding query. That report tells a site about itself. It is not a public league table, so it cannot confirm or replace the Ahrefs ten. Open question Copilot's share of all citations, as opposed to its share of the top 50, is not on the Ahrefs page.
How to use the list
If you sell a product people can buy at a retailer, Copilot is the engine where the catalogue is the citation. A product URL with clean attributes is closer to this list than a thought-leadership post. If you sell advice, Wikipedia and the explainer domains in ranks 4 to 6 are the company you are in, and Forbes is a long way down.
The page-type version of a retailer lead is on most-cited pages. The question of whether those retailers block AI crawlers is not answered by this table, and the join that does exist is news-weighted: which cited domains block crawlers.
Copilot's US list is a shopping index. Amazon 16.8%, Walmart 12.6%, Wikipedia 7.6%. Reddit is not in the top 50.
Share on XVerification status
The ten is Ahrefs, 2 September 2026, over 3 million US queries. A June table reprinted elsewhere was not used, because the live URL has been overwritten. Profound's category row is labelled with its missing sample size. No Copilot top ten was filled in from ChatGPT's list.
Namdev, R. (2026). Most-cited domains in Microsoft Copilot (v1). Retrieved from https://ritiknamdev.com/blog/most-cited-domains-copilot Published under CC BY 4.0 — reuse freely with attribution.
ChatGPT's list, from the same vendor and month, is led by Reddit. Both sit under the cross-engine hub.