HOW SONY SOLD 400 MILLION WALKMANS

Summary from the TLDR Marketing newsletter

Sony built the Walkman by removing features instead of adding them. It cut recording even though research and retailers said customers wanted it. That decision lowered the price to $150, made the device smaller, and gave it a clear purpose. The cassette Walkman sold 200 million units and the Walkman brand reached about 400 million sales across all formats. Use customer data to understand existing behavior, but test new ideas by the behavior you want people to adopt instead of the feature list they say they want.