Summary. Ask an AI engine which product is best and, in this sample, the page it cites is usually a ranked list. OtterlyAI, an AI-visibility tracking vendor, counted 617,985 citations that seven AI engines returned to buyer questions across five US industries from 1 to 30 September 2026. Where the page format could be identified (84% of citations), listicles made up 66.6%. The second finding is about who writes those pages. Among listicles, comparisons and guides with an identified publisher, sites that declare they may earn commissions supplied 44.8%, ahead of brands at 37.4%. The study is dated 14 October 2026, which is the page's last-updated date; no original publication date is shown. The sample is September, US-only, and 295 of its 400 prompts are ranking-style ("best", "top", "cheapest"), so the figures describe that kind of query.
Credibility: MEDIUM. A named research team with a stated method and sample, reached directly as the primary artifact; but a single vendor with a commercial interest in the finding, no downloadable dataset, no trade-press corroboration, and publisher type unidentified for 27.1% of citations. The page discloses that Getfluence, a paid-placement partner of OtterlyAI, is named in the article.
Sources
- OtterlyAI: What Content Do AI Engines Cite? A Study of 617,985 Citations Across 7 Engines and 5 Industries, OtterlyAI blog (Thaylise Nakamoto), last updated 14 October 2026 — https://otterly.ai/blog/content-types-cited-by-ai-study/
Facts
- Sample: five OtterlyAI brand reports (Finance & Insurance, Retail & E-commerce, Educational Platforms, Technology, Sports Brands), each sending 100 buyer questions daily to seven engines; 85,330 unique URLs; 295 of 400 prompts contain ranking words.
- Format: listicles 66.6%, head-to-head comparisons 7.9%, how-to guides 3.6% (11% on open-ended prompts). On comparison-style prompts, comparison pages reach 62.3%.
- Publisher type (450,473 identified citations): brand 38.9%, commission-declaring 36.6%, editorial 11.7% (stated as an upper bound), community 8.6%, institutional 3.9%. Brands publish 35.6% of cited listicles. The commission-declaring share of listicles, comparisons and guides runs from 27.8% in education to 53.1% in finance.
- Engines: Claude cites listicles for 78.2% of classified citations; ChatGPT cites comparisons for 16.1%; Google AI Overviews cites listicles about 45% of the time and forums plus video about 23%; in Google AI Mode listicles rose from about 39% to above 50% during September. Reddit and YouTube account for 92% (AI Overviews) and 98% (AI Mode) of forum and video citations.
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For business owners and marketing leads whose buyers ask AI engines for "best" lists: the answer often leans on someone else's ranking, so find out who wrote the rankings behind yours. In this sample, two in three format-identified citations went to listicles, and the largest group of publishers behind cited lists, comparisons and guides was sites that say they may earn a commission. That moves part of the work onto other people's pages. Your product page still matters, but on a "best X" prompt the engine is often quoting a page you do not own, written by someone with their own reasons for the order. Brands are not shut out. They published 35.6% of the cited listicles, and that share is the part you control. Read the study with the scepticism it invites: OtterlyAI sells visibility tracking, and its own page discloses that a paid-placement partner, Getfluence, is named in the article, a small view of the market the study describes. The sample is a single vendor's September read of US prompts, mostly ranking-style, and your category may look different. Your visibility tracker shows which engines name you; this study suggests which pages to look behind. Check your own cited URLs before any budget moves.
Recommended actions
1. Export the cited URLs behind your tracked prompts from your AI-visibility tool and label each one as listicle, comparison, guide, forum or brand page; the split shows whether your category matches this sample.
2. List the commission-earning and editorial listicles that cite your rivals but not you, and ask your team to check each publisher's disclosure and inclusion terms before anyone spends on placement.
3. Update one comparison or "best for" page on your own site with its criteria and data stated, and write down why you picked that page.
4. Split next month's AI-citation report by engine (Claude, ChatGPT, AI Overviews, AI Mode), because the format mix differs across them.
OtterlyAI: What Content Do AI Engines Cite? A Study of 617,985 Citations Across 7 Engines and 5 Industries, OtterlyAI blog (Thaylise Nakamoto), last updated 14 October 2026 — https://otterly.ai/blog/content-types-cited-by-ai-study/