Sony Walkman

In 1979, Sony's market research delivered a clear verdict: nobody would buy a cassette player with no recording function and no speaker. Consumers said so directly when asked. Retailers balked at the price. Sony's own engineers pushed back. Co-founder Akio Morita overruled all of them, reportedly so certain he offered to resign if the product flopped. It went on to sell roughly 400 million units and invent the entire category of personal audio, a behavior that survived through CD players, iPods, and streaming earbuds.

For founders and operators, this case sharpens one of the trickiest judgment calls in product: when to trust the data and when to recognize that the data literally cannot exist yet. It probes how you separate a genuinely new behavior from a bad idea wearing the same disguise. Why Morita was so sure, and what that should teach you about your own surveys, is the part the app holds back.