The Sources AI Cites Most: G2, Reddit, Wikipedia and Beyond
It depends on the engine. In 959 answers to software buying questions in Citepoint's October 2026 index, Google's AI Overviews cited Reddit in half of its answers and YouTube in over a third, Gemini leaned on roundups and review sites like Zapier's blog and G2, and ChatGPT pointed mostly at the recommended brands' own websites (70% of its citations). Wikipedia wasn't cited once. Across all kinds of questions, larger studies rank Reddit, YouTube, LinkedIn, Wikipedia, Forbes and G2 as the most-cited sites.
Key takeaways
- Google's AI Overviews cited Reddit in 50% and YouTube in 36% of the answers where an Overview appeared.
- 70% of ChatGPT's citations pointed at the websites of the brands it recommended, against 27% for Gemini and 21% for AI Overviews.
- Gemini cited the most sources per answer (9.2 on average), led by Zapier's app roundups and G2.
- Wikipedia, a top source in broad studies, was never cited for software buying questions.
What did we measure?
Every month, Citepoint's AI Recommendation Index asks 20 buyer questions in each of 16 software categories, such as CRM, help desk, accounting, payments and AI app builders, on ChatGPT, Gemini and Google AI Overviews, in US English. In October 2026 that produced 959 answers: 320 from ChatGPT, 320 from Gemini and 319 from AI Overviews, of which Google showed an Overview for 314. Together they contained 6,128 citations to 1,529 different domains.
For each source we counted the answers that cited it at least once, so a page cited three times in one answer counts once. Domains are grouped by site, so en.wikipedia.org counts as wikipedia.org.
Which sources were cited most?
Leaving out the vendors' own websites, these were the most-cited sources across all 959 answers:
| Source | Answers citing it | Mostly cited by |
|---|---|---|
| 166 | Google AI Overviews | |
| YouTube | 115 | Google AI Overviews |
| Zapier | 68 | AI Overviews and Gemini |
| Quora | 35 | Google AI Overviews |
| Medium | 33 | AI Overviews and Gemini |
| G2 | 30 | Gemini |
| GitHub | 29 | ChatGPT and AI Overviews |
| 23 | Google AI Overviews | |
| Forbes | 17 | Google AI Overviews |
| PCMag | 13 | Gemini and AI Overviews |
| TechRadar | 12 | Google AI Overviews |
| Gartner | 11 | Google AI Overviews |
| Capterra | 5 | Spread thinly across all three |
| Wikipedia | 0 | None |
How does each engine choose differently?
| Engine | Citations per answer | Share pointing at recommended brands' own sites | Leading third-party sources |
|---|---|---|---|
| ChatGPT | 3.7 | 70% | Small software roundup sites, each in a handful of answers |
| Gemini | 9.2 | 27% | Zapier (8% of answers), G2 (8%), The Digital Project Manager (6%) |
| Google AI Overviews | 6.4 | 21% | Reddit (50%), YouTube (36%), Zapier (13%), Quora (11%), LinkedIn (7%) |
ChatGPT reads the vendors. Seven in ten of its citations went to the websites of the brands it recommended: pricing pages, feature pages and comparisons. For ChatGPT, what your own site says, and how clearly it says it, carries the most weight.
Gemini reads the roundups. It cited more than twice as many sources per answer as ChatGPT, and its favourites were "best apps" listicles, such as Zapier's, and review sites such as G2. Being included in the roundups and review grids for your category is the lever here.
Google's AI Overviews read the community. Half of all Overviews cited Reddit, and more than a third cited YouTube, with Quora and LinkedIn behind them. Overviews draw on what people say about products, not just what vendors and editors write.
Why didn't Wikipedia appear?
Because these were buying questions. Wikipedia explains what a CRM is; it doesn't say which CRM a five-person agency should pick. In a broader study of 30 million citations across all kinds of questions, published by Peec AI in October 2026, Wikipedia ranked fourth overall and was a top source for ChatGPT and Perplexity, but was absent from Google's AI platforms. The sources that matter depend on the kind of question your buyers ask.
What do larger studies find?
Peec AI's 30-million-citation analysis ranked the ten most-cited domains across ChatGPT, Gemini, Perplexity, AI Overviews and AI Mode as Reddit, YouTube, LinkedIn, Wikipedia, Forbes, G2, Yelp, Facebook, Medium and TechRadar. Reddit and YouTube were in every engine's top five. G2 was in Perplexity's top five and no other's. That matches what we see for software: community platforms lead on Google, and review sites matter most where buyers compare business tools.
What should you do with this?
- For ChatGPT, fix your own site first. Publish pages that answer buyer questions directly: comparisons, alternatives and "best for" pages with current prices and limits. Make sure OAI-SearchBot can read them; the free AI Crawler Checker checks.
- For Gemini, get into the roundups. Find the listicles and review categories it cites for your questions, keep your G2 profile current, and give roundup authors a reason to include you.
- For Google's AI Overviews, be part of the conversation. Answer real questions on Reddit and Quora as yourself, with disclosure, and publish short videos that answer buyer questions.
- Check your own questions. These are averages across 16 categories. The sources cited for your questions may differ, so look before you invest. Citepoint's Mentions ranks the review sites, directories and articles AI cites for your tracked questions and drafts the listings and pitches. The free scan shows who AI recommends for three of your buyer questions.
What are the limits of this data?
It covers software buying questions only, in US English, from one answer per question per engine in one month. Claude and Perplexity weren't part of the index. Citation counts show where engines look, not how much each source sways the answer. Treat the numbers as a map of where to look, and check them against your own questions.
Frequently asked questions
Which source matters most for AI visibility?
It depends on the engine your buyers use. In our October 2026 data, ChatGPT mostly cited brands' own websites, Gemini favoured roundups and review sites like G2, and Google's AI Overviews leaned on Reddit and YouTube.
Should I post on Reddit to get cited by AI?
Only where you can genuinely help, as yourself and with disclosure. AI Overviews cite Reddit because it holds real experience. Promotional posts tend to be removed, and they don't create that.
Is a G2 profile worth it?
For business software, yes. G2 was among Gemini's most-cited sources in our data and in Perplexity's top five in a 30-million-citation study. Keep it complete and current, and ask real customers for reviews.
Why does ChatGPT cite brands' own websites so often?
When it recommends products, ChatGPT tends to back each one with the vendor's own pages, such as pricing and features. That makes the clarity and accuracy of your own site the first thing to get right for ChatGPT.