Dyson

James Dyson spent roughly five years and built about 5,127 prototypes before his bagless vacuum worked consistently. He wasn't even a trained engineer; he was an industrial designer who noticed a sawmill's cyclone separator pulling dust from spinning air without a filter and wondered if it could work in a home. The established UK and US vacuum makers, fat on profitable bag businesses, wanted nothing to do with it. He licensed it to Japan, then launched his own brand, and by the mid-1990s the DC01 was the UK's best-selling vacuum.

For founders and operators attacking an entrenched market, this is the case on persistence as a strategy and design as a weapon. What Dyson did after the product worked mattered as much as the engineering itself, and it turned years of failure into a brand narrative. It sharpens the decision of which problem every customer in your market accepts as normal that no incumbent is motivated to fix.