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Zombie stats: Where the numbers AI quotes come from

Following one number back to its source

We asked ChatGPT, Perplexity, Gemini, Claude and Google’s AI Overviews 200 questions that call for a number, the kind people ask every day. Then we clicked the citations, and kept clicking. Here is one trail, from the answer to the end.

Google AI Overviews

What percentage of salespeople give up after one follow-up?

44% of salespeople give up after just one follow-up attempt.

A sales firm’s stats page2020

44% of salespeople give up after one follow-up attempt (source).

A freelance writer’s sample articleby 2017

80 Percent of Sales Require 5 Follow-up Calls after Meeting; 44 Percent Salespeople Give Up After One Follow-up

No study behind itThis page cites no research.

  1. In the answer

    Every assistant got the same question: “What percentage of salespeople give up after one follow-up?” All five assistants gave the same figure, and only ChatGPT said the evidence behind it was unclear.

  2. One click in

    Google AI Overviews cited a sales firm’s stats page, from 2020. The number is right there. Its “source” link goes to a writing sample.

  3. Two clicks in

    That leads to a freelance writer’s sample article, online by 2017. The number is in its headline. It lists two slide decks, a blog list and two news stories. None is a study of follow-ups.

  4. The end of the trail

    That’s where the trail ends. We tried every other route to this number we could find, and each one stopped at a page that cites no research. This is what we mean by a zombie stat: a number that keeps getting repeated with no study behind it.

Most numbers aren’t like this one. The trouble is that you can’t tell which ones are from the answer. This one came with the same confident tone and the same kind of citation as any other, and all five assistants agreed on it. So we followed 1,285 statistics the same way.

Fewer than half lead back to a study

We took a random sample of the statistics each assistant cited, 1,285 in all, and walked every trail the same way: the cited page, then that page’s source, up to five pages deep. Where a page named a source without a link, we searched for it.

40% reached a study that says the same thing. Another 8% reached the study, but the number or its context had changed on the way. The rest never got there: 40% stopped at a source we couldn’t check, because it was locked, gone or silent on the number, and 11% led nowhere at all.

Four in ten trails reached a study that says the same thing

Each square is one in a hundred of the 1,285 statistics we traced, sorted by where its trail ended.

  • 40%SourcedWe found the study, and it says the same thing.
  • 8%ChangedWe found the study, but the number, who was asked, where or when is different.
  • 40%Can’t checkA page names a real source, but the number isn’t in it, or the source is locked or gone.
  • 11%NowhereNo study anywhere on the trail. Every page repeats the number and credits no one.

The last 1%: trails whose pages wouldn’t load for us.

ChatGPT did best, and quoted the fewest numbers: 1.3 per answer, against 6.8 for Claude. The other four landed between 38% and 46%, too close to rank.

ChatGPT quoted the fewest numbers, and sourced the most

The same hundred squares for each assistant, from its own sample of cited statistics.

  1. ChatGPT

    57% sourced

    1.3 statistics per answer

  2. Perplexity

    46% sourced

    2.2 statistics per answer

  3. AI Overviews

    39% sourced

    4.8 statistics per answer

  4. Gemini

    38% sourced

    6.2 statistics per answer

  5. Claude

    38% sourced

    6.8 statistics per answer

To check this wasn’t down to the questions we picked, we also traced 300 statistics from Google AI Overviews answers to real everyday searches. 40% were sourced, about the same share.

AI mostly cites pages that repeat the number

The AI mostly wasn’t making numbers up. The page it cited had the figure 82% of the time. But only 21% of the pages cited for a number were the original research.

More than half were company blogs. Add news stories and statistics roundups and you have most of the citations: pages that repeat figures from somewhere else, often without linking to it.

How often each kind of cited page led to the study

Every page an assistant cited first for a number, by kind. Each column’s width is its share of those citations. Green is how often its trails reached a study that says the same thing.

62%

Research firm13% of citations

Research firm or survey: 13% of first citations, 62% of them sourced.

61%

Government7% of citations

Government or official body: 7% of first citations, 61% of them sourced.

37%

Company blog54% of citations

Company blog: 54% of first citations, 37% of them sourced.

37%

News10% of citations

News or magazine: 10% of first citations, 37% of them sourced.

35%

Stats roundup8% of citations

Stats roundup: 8% of first citations, 35% of them sourced.

41%

Other8% of citations

Other: 8% of first citations, 41% of them sourced.

The first page made a big difference. When a trail started at a research firm or a government page, it reached a matching study 61% of the time. From a company blog, 37%; from a statistics roundup, 35%. Even research firms fell short 38% of the time, often because the full report sat behind a form.

A citation tells you where the AI found a number, not where the number came from.

Some numbers change along the way

Reaching the study didn’t always mean the number held. Of the statistics that got there, 17% had changed on the way. The digits moved only about one time in four. Usually it was the context: what was measured, the year, the source, or who was asked.

What changed, across every change we logged

The number changed
26%

What was measured changed
20%

The year changed
17%

The source changed
16%

Who was asked changed
14%

The place changed
4%

In one case, a 2004 study of 15 women judging health websites turned into a claim about first impressions of every website. Below are the clearest trails we followed, each checked by hand.

Watch a number lose its context

Each trail runs from the original study to an answer an assistant gave in October 2026. Step along it: the number stays, and the words around it change.

AskedWhat percentage of first impressions of a website are design-related?

The study · Sillence and colleagues, CHI, 2004

Of the comments 15 women made about rejecting or mistrusting health websites, 94% were about design.

A 2004 study watched 15 British women judge health websites, and 94% of their comments about rejecting a site were about design. Twenty years of retelling made it “94% of first impressions are design-related”, and Google AI Overviews states it as fact.

Step 1 of 4

The zombie stats

Ask five assistants the same question and you’ll often get five different numbers. On 28 of the 71 questions where all five gave a percentage, we got four or five different figures.

One question, five answers, from 49% to 96%

Asked “What percentage of marketers use marketing automation tools?”, word for word, on the same day.

0%100%

49–51%AI Overviews

62%ChatGPT

70–79%Gemini

81%Perplexity

96%Claude

  • ChatGPTThere isn’t one universal figure, it varies by survey and what counts as “marketing automation.” One commonly cited survey found 62% of U.S. digital marketers used automation software, but that data is from 2020, so it may not reflect current adoption.

  • PerplexityApproximately 81% of marketing organizations use marketing automation.

  • GeminiAcross major industry benchmarks, between 70% and 79% of marketers and companies use marketing automation tools in some capacity

  • Claude96% of marketers have used a marketing automation platform or plan to use one

  • AI OverviewsRoughly 49% to 51% of companies and marketing teams currently use marketing automation tools, according to industry benchmarks from Moosend and related research studies.

Across those questions, the typical gap between the highest figure and the lowest was 16 points.

On 31 of 71 questions, the five figures were 20 points or more apart

Every question where all five gave a percentage, one line each, from the lowest figure to the highest. Closest at the top.

What percentage of searches include local intent such as nearby or near me? 46% to 46%How many social media users follow at least one brand? 90% to 90%What percentage of online shopping carts are abandoned? 70% to 70%What is the average conversion rate for ecommerce websites? 3% to 3%What percentage of students take at least one online course during their studies? 54% to 54%What percentage of social media users access platforms on mobile devices? 99% to 99%What is the average conversion rate for websites? 3% to 4%What percentage of sales leads convert to customers on average? 4% to 5%What percentage of small businesses survive their first five years? 49% to 51%What is the average engagement rate for organic social media posts? 0% to 2%What percentage of employees work remotely at least part time? 22% to 24%How many people carry credit card balances month to month? 45% to 48%What percentage of small businesses are owned by women? 40% to 43%What percentage of web traffic comes from mobile devices? 57% to 60%What percentage of organizations report AI has improved decision making? 50% to 53%What percentage of users use ad blockers on websites? 30% to 33%What is the average completion rate for massive open online courses? 7% to 10%How often do users click the first organic result? 25% to 29%What percentage of households own a smartphone? 87% to 91%What percentage of people have student loan debt? 16% to 21%How often do websites use responsive design? 90% to 95%How many households have no emergency savings? 21% to 27%What percentage of leadership positions are held by women? 27% to 33%How many students drop out before completing their degree or certificate? 30% to 39%What percentage of ecommerce revenue is generated by repeat customers? 40% to 50%How many small businesses have a website? 73% to 83%What percentage of people live paycheck to paycheck? 48% to 59%What percentage of a salesperson's time is spent actually selling? 29% to 40%What percentage of workers perform gig or freelance work in addition to a main job? 8% to 20%What percentage of marketing budgets is typically spent on digital channels? 55% to 68%How often do users click on featured snippets or answer boxes? 9% to 22%What percentage of shoppers abandon checkout because of shipping costs? 40% to 54%What percentage of searches are performed on mobile devices? 53% to 67%What is the average percentage of company budget spent on AI? 2% to 17%What percentage of software features are rarely or never used? 64% to 80%What percentage of data breaches are caused by human error? 60% to 78%What percentage of adults use some form of prescription medication regularly? 50% to 68%What is the average win rate for outbound leads? 2% to 20%What percentage of emails are opened on mobile devices? 42% to 61%How many adults experience sleep disorders such as insomnia? 13% to 33%What percentage of free trial users convert to paying customers? 5% to 25%What percentage of SaaS spend goes on unused licences? 30% to 50%What percentage of students report concerns about mental health during studies? 63% to 85%How many marketers report using email marketing regularly? 63% to 86%What percentage of marketers use social media for promotion? 73% to 97%What percentage of adults use social media? 70% to 95%What percentage of adults are classified as obese? 16% to 42%What is the average win rate for inbound leads? 4% to 30%What percentage of customers will pay more for a better experience? 59% to 86%What percentage of people read the terms and conditions before accepting them? 9% to 37%What percentage of software development teams use AI code assistants? 66% to 97%What percentage of households have internet access? 58% to 93%How many people have credit card debt? 23% to 60%How many AI projects fail to reach production? 46% to 88%How many online purchases are made via marketplaces versus individual stores? 30% to 72%How many online shoppers use social media to discover products? 39% to 82%What percentage of marketers use data analytics for campaign decisions? 44% to 90%What percentage of marketers use marketing automation tools? 50% to 96%How often do organizations experience ransomware attacks each year? 25% to 72%What percentage of companies use AI in their operations? 37% to 88%How often do people check social media each day? 33% to 85%How often do employees report feeling burned out? 27% to 82%What percentage of consumers use social media to research purchases? 26% to 82%What percentage of students enroll in higher education after finishing secondary school? 44% to 100%What percentage of consumers ignore online ads? 37% to 93%What percentage of consumers trust AI recommendations for purchases? 33% to 89%What percentage of small businesses sell products or services online? 23% to 85%How much more likely are customers to buy when free shipping is offered? 20% to 82%What percentage of data breaches involve compromised credentials? 22% to 90%

Closest20 points or more apartFurthest apart

When all five agreed, the number wasn’t any more likely to check out. They gave the same figure on 10 questions, and of the 5 we traced, 2 were sourced. The statistics quoted by three or more assistants did no better: 11 of 29 were sourced.

Four were quoted by all five assistants, and we couldn’t find a study behind any of them.

Numbers every assistant quoted, with no study we could find

Four statistics every assistant gave us, each with a trail that ends at a page citing no research.

  • 44%

    Salespeople who give up after one follow-up

    Every trail ends at a page that cites no research, one of them a freelance writer’s sample article. Its full trail opens chapter 1.

    Quoted by all five

  • 90%

    Social media users who follow at least one brand

    Stated with no source. No study with this figure was found.

    Quoted by all five

  • 75%

    Searchers who never scroll past the first page of results

    Repeated with no source, often credited to an old marketing roundup that no longer carries it. No study was found.

    Quoted by all five

  • 5 to 25 times

    How much more it costs to win a customer than to keep one

    A 2014 Harvard Business Review article gives the range “depending on which study you believe”, and names none.

    Quoted by all five

The 29 statistics AI repeats most

Each was quoted by at least three of the five assistants, most often first, and its trail checked by hand.

  1. 95%

    Generative AI pilots that fail to deliver a measurable financial return

    MIT NANDA’s 2025 report says 95% of organizations got no return from generative AI. That isn’t the same as 95% of pilots failing.

    5 of 5ChangedStudy from 2025
  2. 44%

    Salespeople who give up after one follow-up

    Every trail ends at a page that cites no research, one of them a freelance writer’s sample article. Its full trail opens chapter 1.

    5 of 5Nowhere
  3. 4% to 10%

    Unhappy customers who actually complain

    Goes back to TARP’s 1979 research for the White House consumer office. Its author says rates that low apply to small purchases; in 2016, 22% to 41% complained about their most serious problem.

    5 of 5ChangedStudy from 1979
  4. 2 hours 21 minutes

    Time people spend on social media each day

    DataReportal’s Digital 2025 report, from GWI survey data: the typical internet user spends 2 hours 21 minutes a day on social media.

    5 of 5SourcedStudy from 2025
  5. 46%

    Google searches with local intent

    Traces to a 2018 social post about a slide at a search conference. Google never published it, as far as we could find.

    5 of 5Can’t check
  6. 90%

    Social media users who follow at least one brand

    Stated with no source. No study with this figure was found.

    5 of 5Nowhere
  7. 94%

    First impressions of a website that are about its design

    Began as a 2004 study of how 15 women judged health websites. Its full trail is in chapter 4.

    5 of 5ChangedStudy from 2004
  8. 75%

    Searchers who never scroll past the first page of results

    Repeated with no source, often credited to an old marketing roundup that no longer carries it. No study was found.

    5 of 5Nowhere

What to do with a statistic from an AI

Treat it as a lead rather than a source. Here’s what we’d do, whether you use these numbers or publish them.

If you use them

  1. Follow the citation, then follow it again.

    If the cited page is a list of statistics or a company blog, use its own link to go one page further. Keep going until you reach the study itself, or until you can’t.

  2. Check who was asked, how many, and when.

    Most of the changes we found were in the context, not the digits: one country’s poll, a ten-year-old study, fifteen people.

  3. Don’t take agreement as a check.

    Five assistants giving the same number isn’t five sources. The numbers they repeated most were no better sourced than the rest.

If you publish them

  1. Put the method next to the number.

    The sample, the date and a link to the source, on the same page as the figure, so the next page, and the next answer, can trace it back to you.

  2. Keep the findings in the open.

    Reports behind a form were a common dead end: even trails that started at a research firm fell short 38% of the time. Put the headline numbers and the method on an open page.

  3. See which page AI cites for your numbers.

    It is often a roundup or a blog that copied you, sometimes with an older figure. That page decides what people hear.