When Your Website Is Vague, Google States Invented Specifics as Fact 80% of the Time

Herringbone asked Google and ChatGPT two questions each about 600 real businesses: 200 dental practices and orthodontists, 200 personal-injury law firms, 200 home service companies. That produced 1,200 graded answers, 601 of them checked by hand. The result: 27% of Google AI Overviews answers and 20% of ChatGPT answers contained something the business does not publish.

The number that should worry an owner is the next one. When a business website is vague, Google states invented specifics as fact 80% of the time. ChatGPT does it 10% of the time, because it usually names the directory the detail came from.

A business that says nothing about its hours or its prices does not get a blank in the answer. It gets a filled blank, and on one of the two engines the fill usually arrives with no hedge, in four cases out of five.

Two engines, one silence, two different fills

Both engines fabricate. The difference is what the reader can do about it.

When ChatGPT pulls a detail from a directory, it tends to name the directory. A reader who cares can follow the pointer and decide whether to trust that listing over the business’s own page. When Google fills the same silence, Herringbone found it does so “without signalling any uncertainty in four out of five cases.” Their phrasing: “That is the finding with teeth.” An answer that is sometimes wrong is a known cost of any summarizer. An answer that is wrong and carries nothing telling the reader to check is a different product.

A caveat on method, in the authors’ own terms. Google answers were generated through Gemini 3.5 Flash with Search grounding, ChatGPT answers through the OpenAI Responses API with web search. Herringbone says this is “the model that powers AI Overviews.” That is their assertion, and the study is an API run, not a live-interface test. Read the split between the engines as a strong signal about how each one handles missing facts, and keep the exact percentages loose.

The hours problem is the whole problem in miniature

Hours are the simplest fact a business can publish, and only 55% of the businesses in the sample publish them cleanly.

Of 59 businesses publishing no hours on their own site, 46 had set their Google listing to “Open 24 hours.” The engine did what any reader would do with that input. A separate pattern: a 24/7 phone line was read as 24-hour opening by Google 25% of the time and by ChatGPT 21% of the time. A promise about the phone became a claim about the door.

In both cases the model read a signal the business itself left lying around, a listing the business itself had set, or an ambiguous promise, and treated it as the fact of record because no clearer fact was available.

Publishing plainly is worth 21 points on Google and 16 on ChatGPT

Herringbone split the businesses by whether their site states things plainly. For the plain publishers, accuracy was 84% on Google and 89% on ChatGPT. For the vague or silent ones, 63% and 73%. In their words: “Publishing clearly lifts Google’s accuracy by 21 points and ChatGPT’s by 16.”

These are sampled estimates, “with a margin of a few points,” per the page. The direction does not depend on the margin. The fix is editorial. The businesses that are answered correctly are the ones whose pages say one thing in plain words. Herringbone’s checklist adds the second half: repeat that one thing everywhere else the business appears.

That second half matters as much as the site itself. The invented hours came from the business’s own Google listing and its own 24/7 wording.

HubSpot ran the same experiment at enterprise scale

Aja Frost, formerly of HubSpot, published a year of the company’s AI-search experiments on Growth Unhinged. The numbers are HubSpot-internal and self-reported by a former employee, so treat them as one company’s log rather than a benchmark. Read that way, they line up with Herringbone’s findings on almost every point.

Start with what did nothing. HubSpot published an llms.txt and planted easter eggs in it to detect reads. No bot visits on the easter eggs. Nothing in the server logs. Direct submission to Bingbot and Googlebot produced nothing. We covered Ahrefs’ 97%-zero-reads figure for llms.txt in An AEO Best Practice, Debunked by Its Own Data; HubSpot’s easter-egg test is first-party confirmation of the same result, and Frost cites the Ahrefs figure herself.

Now what worked. HubSpot generated 141 industry × use-case pages. ChatGPT’s bot logged 15K crawls in a few weeks. Citations “hovered around 16%” early. “Ultimately, 92% were cited, increasing visibility by 49%.” Fifty glossary pages lifted visibility 35% on awareness questions and 26% on consideration and decision questions, and moved overall citation share from 1.97% to 3.2%.

The most Herringbone-like finding is the pricing one. HubSpot’s pricing page was rendered in JavaScript. The company improved answer accuracy for five of six products by publishing the prices in plain blog posts. The sixth, Sales Hub, got worse until third-party listings were corrected. The engine was reading the listings. Same mechanism as the 46 businesses with a 24-hour Google listing, at enterprise scale.

Frost’s headline outcome: “HubSpot was the #1 most visible CRM in AI search and qualified leads from AI were up 1,850%.” The piece discloses no base for the 1,850%. Keep the direction, drop the magnitude.

Crawls, then citations, then visibility

One more HubSpot result deserves its own section because it says something about order. HubSpot pre-rendered its pages, cutting load time to roughly one-tenth of a second, 6.4 times faster than before. AI bot crawls rose 1,600%. Traditional crawlers rose 30%. Citations rose nearly 40%. AI referral traffic rose 6%.

Frost’s own summary: “Crawls happen first, then citations, then visibility.” And, on the last step, “citation and traffic trends are not proportionate.” A business that measures only the last number will conclude nothing happened while everything upstream was moving. We looked at which AI-search KPI to fund in Five Companies Just Named the AI-Search KPIs They Actually Track. Frost’s sequence is the reason the early KPI has to be crawls or citations. Traffic arrives last and arrives smaller.

Silence is a governance failure with a measured cost

The two studies describe one control failure at two sizes. Herringbone’s small businesses did not publish hours. HubSpot did not publish prices in a form a crawler could read. In both cases something other than the website became the source of record: a Google listing the business itself had set, or a third-party listing HubSpot did not control. On Google, the reader was not told.

We wrote about the attribution side of this, where AI Overviews send traffic that analytics files under Direct, in AI Overviews Send You Traffic. Your Analytics Files 22% of It Under Direct. Fabrication is the other side. Attribution loss means you cannot see the customer the engine sent you. Fabrication means the engine sent the customer somewhere you never said you were, at an hour you were closed.

The remedy is a publishing discipline. We described the two audiences a page now serves in Your Docs Have Two Audiences Now. Read together, Herringbone and Frost imply one operating rule: every fact a buyer would ask an engine about must exist on your own site, in plain text that survives a single fetch, and must match every listing that carries your name.

Do this now

Herringbone published a five-item checklist with an owner for each item. Use their assignment as written.

1. Owner: open your Google Business Profile and check the hours. If it says “Open 24 hours” and you are not, fix it today.
2. Owner: search your own business in Google and in ChatGPT. Read the answers as a customer would. Note every specific you did not publish.
3. Website editor: rewrite “available 24/7” to what is actually available. A night phone line is a night phone line.
4. Agency: audit the directories before touching site copy. HubSpot’s Sales Hub accuracy did not recover until the listings were corrected.
5. Agency or developer: make hours say one thing everywhere. Same words on the site, the profile and every directory.

Then, if you run a marketing team rather than a dental practice, add HubSpot’s two findings. Publish the facts buyers ask about, prices first, as plain pages, and measure crawls and citations before you measure traffic.

The engine will answer the question either way. The only choice you have is whether it answers with your words or with someone else’s.

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This analysis synthesizes Does AI Get Your Business Details Right? (Herringbone, Clara Sherman and Dan Hinckley, September 2026) and Inside 12 months of AI search experiments (Growth Unhinged, Aja Frost, ex-HubSpot, September 2026).

Victorino Group helps firms turn the facts buyers ask AI engines about into a published, crawlable, consistent surface. Let’s talk.