Flaw of the Week · November 9, 2026
Appeal to Popularity: Two Million Copies Can't Be Wrong
The flawed argument
A diet book's publisher advertised: "Two million copies sold! The results speak for themselves."
Why it fails
Sales measure marketing, not truth. Millions of people have bought ineffective products, from miracle cures to lottery tickets. Popularity is evidence of appeal, not evidence of correctness.
The answer
The flaw is an appeal to popularity: treating "many people believe it" as proof that it is true.
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Last updated October 12, 2026