Which domains do ChatGPT, Gemini and Google AI Overviews cite for B2B marketing questions? We checked 900 answers

We built 300 English queries with no brand names, 75 for each funnel stage: awareness, consideration, evaluation and decision. They cover nine topics: content marketing, SEO, demand generation, ABM, marketing automation, analytics, agency selection, tool comparisons and general B2B marketing. Query types include "what is", "how to", "best tools for", "X vs Y" and vendor selection.

Typical examples: "what is B2B content marketing and how does it drive pipeline" (awareness), "gated vs ungated content for B2B lead generation" (consideration), "best content marketing platforms for B2B teams" (evaluation) and "how to choose a B2B content marketing agency" (decision).

We ran every query in ChatGPT, Gemini and Google AI Overviews through our AI Visibility platform. The market was the US, the language English, and no account was logged in. Perplexity is not in the data because the provider's Perplexity model was unavailable.

For each answer we saved the full text and every source link, with a flag for whether the link appears in the answer text itself. Domains are normalized, so blog.hubspot.com and hubspot.com count as one.

Denominator. Shares below are calculated from answers that contain sources, not from all answers. That matters because the engines differ a lot in how often they show sources at all.

	ChatGPT	Gemini	Google AI Overviews
Answers	300	300	300
Answers with sources	268 (89%)	156 (52%)	297 (99%)
Average links per answer with sources	16.5	7.0	8.3
Distinct domains	1,825	370	1,002

Gemini shows sources far less often than the other two, and the gap depends on the stage. At the awareness stage only 22 of 75 Gemini answers had sources, and at consideration 24 of 75. At evaluation it was 68 of 75, and at decision 42 of 75. Every Gemini percentage below rests on 156 answers, so treat it as a rough signal.

The google.com row is mostly support.google.com and developers.google.com, which means GA4 documentation.

Of these 13 domains, six are software vendors, two are agencies, two are review or directory sites, and one each is an analyst firm, a social network and documentation.

ChatGPT is the most concentrated engine at the top and the most scattered below it. hubspot.com appears in more than a third of its answers with sources. But the top 10 domains cover only 11.7% of all domain mentions, because ChatGPT cites 1,825 different domains.

"Used" is not the same as "cited"

ChatGPT lists links it browsed alongside links it actually places in the answer text. Overall, 39% of its links appear in the text. For Gemini the number is 99.6%. Google AI Overviews gives one source list, so we cannot split it.

The split changes the picture for ChatGPT. hubspot.com was used in 101 answers and cited in text in 77. rework.com was used in 26 and cited in 3. Two logo sites, iconlogovector.com (21 answers) and seeklogo.com (17), appear as used sources but were never cited in text. They show up mainly at the evaluation stage, where queries compare tools, and ChatGPT apparently pulled logo images for them. medium.com was used in 16 answers and cited in none.

If you count every link as a citation, logo aggregators look like major sources. They are not.

No Gemini domain reaches 5% of answers with sources. The top 10 cover 11.1% of domain mentions across 370 domains. Seven of the ten are vendors, two are agencies and one is an analyst firm.

At the decision stage, where Gemini returns sources for 42 of 75 answers, small agencies and niche vendors lead. howllouder.com is first with 4 answers, followed by a group tied at 3 that includes saashero.net and explorecarbon.com. At evaluation, Gartner (7 answers), Zapier and influ2.com (5 each) lead.

Four of the top ten are video, social or community platforms. YouTube alone is in two of every three answers, and it leads at every funnel stage (between 58% and 81% depending on the stage). Google AI Overviews is also the most concentrated engine: its top 10 cover 24.7% of domain mentions.

hubspot.com is the only domain in the top 10 of all three engines. Widen the lists to the top 20 and gartner.com joins it.

Pairwise, ChatGPT and Google AI Overviews share more than either shares with Gemini. Their top 10 lists have adobe.com, demandbase.com, hubspot.com, linkedin.com and salesforce.com in common, with demandbase.com in a tie at the cutoff. ChatGPT and Gemini share only hubspot.com. Gemini and Google AI Overviews share gartner.com, hubspot.com and zapier.com.

• ChatGPT. At awareness, hubspot.com (41% of answers with sources) and salesforce.com (29%) lead. At evaluation, hubspot.com is still first at 51%, but rankite.com, iconlogovector.com, itechguides.com and seeklogo.com follow. At decision, an agency leads: stackmatix.com (25%), with hubspot.com, pedowitzgroup.com, rework.com and forrester.com behind it.
• Gemini. Source coverage itself depends on the stage, from 29% of answers at awareness to 91% at evaluation.
• Google AI Overviews. YouTube leads at every stage. Reddit is in the top three at consideration, evaluation and decision, and LinkedIn is in the top three at awareness, consideration and decision.

These are readings of the data, not tested playbooks.

• Treat each engine as its own channel. A domain that ranks well in ChatGPT is not likely to do the same in Gemini or Google AI Overviews.
• For ChatGPT, vendor-owned content and review sites do most of the work. Track cited-in-text separately from used. A link that was only browsed may not influence the answer the reader sees.
• For Google AI Overviews, video and community presence is part of the picture. YouTube, Reddit, LinkedIn and Quora together account for much of what this engine cites.
• For Gemini, expect gaps. Many answers carry no sources at all, and the ones that do spread across hundreds of domains. A single citation count is a weak metric there.
• Always compute shares from answers that have sources. Otherwise Gemini's numbers look smaller than they are and ChatGPT's look larger.

• 🇺🇸 US market, English, no login. Other markets and logged-in sessions can differ.
• Ties at the cutoff. At each engine's top-10 boundary several domains tie. We show the tied groups instead of an arbitrary cut.
• Normalization is simplified. We merge subdomains by the last two parts of the host, with exceptions for domains like co.uk. That is why google.com combines several Google properties.
• Gemini sample. Its percentages rest on 156 answers with sources.
• Types are our labels. We typed the top domains by what each site is. Some are judgment calls, for example an agency that also sells software.
• Cited versus used. ChatGPT and Gemini separate them reliably. Google AI Overviews does not.