I asked ChatGPT, Gemini and Claude: what percentage of salespeople give up after one follow-up? All three said 44%. Then I asked Claude for the original study, and it wrote: "There is no original study behind the 44%. I found no one who ran it, no year of fieldwork and no sample size." This kit gives you that question and a few more checks, so you don't put a zombie number into your next presentation.
#1. What a zombie stat is
A number that keeps getting copied long after its source is gone, changed, or never existed. Trakkr Research traced 1,285 statistics that five AI assistants quoted (ChatGPT, Perplexity, Google AI Overviews, Gemini, Claude) and found:
| Result of the trace | Share |
|---|---|
| Leads to a study that says the same thing | 40% |
| Leads to a study, but the number or context changed | 8% |
| Stops at a source nobody can check | 40% |
| Leads nowhere | 11% |
The AI usually didn't invent the number. The page it cited really contained it, but only about 1 in 5 cited pages was the original research. Most were company blogs.
#2. The one prompt
Paste this after any AI answer that contains a number:
Find the original study behind that number. Who ran it, in which year, with how many people? Give me the link. If there is no original study, say so plainly and correct your answer.What happened in my test (31 Oct 2026, same question in all three, the recording in the Reel):
| Assistant | First answer | After the source question |
|---|---|---|
| ChatGPT | 44%, "isn't well verified" | (not asked) |
| Gemini | 44%, cited a sales lead-generation site, "often considered an unverified industry benchmark" | (not asked) |
| Claude | About 44%, "its original source is murky, so treat it as a rule of thumb" | "There is no original study behind the 44%". The closest source it found: a 1987 business book, "with no survey, sample or citation behind it" |
Claude also said the book trace comes from a single blog and that it hadn't checked the book itself, which is exactly the kind of caveat you want. Its last line: "If you need a number for a presentation, I'd drop the 44%."
#3. Five zombie stats AI loves to quote
All five assistants in the Trakkr study quoted these, and the trail ended without a real study behind the claim:
- 44% of salespeople give up after one follow-up.
- 90% of social media users follow at least one brand.
- 75% of searchers never scroll past the first page.
- Winning a customer costs 5 to 25 times more than keeping one (the usual source names no study).
- 94% of first impressions are design-related (traces back to a small 2004 study about health websites).
If you see one of them in a slide, ask for the source.
#4. Check a number yourself in 2 minutes
- Copy the exact number and the claim into a search engine with the word "study".
- Open the oldest result, not the newest. Newer pages copy older ones.
- Look for a method: who was asked, how many, when. No method, no study.
- If the only source is a company that sells the thing the number promotes, treat it as marketing.
- Still unsure: write "about" and the year, or leave the number out. A presentation without a fake number is stronger than one with it.
#Sources
- Trakkr Research, Study 013 (Mack Grenfell, 28 Oct 2026): Zombie stats: where the numbers AI quotes come from
- My own test in ChatGPT, Gemini and Claude on 31 Oct 2026.
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