What's the Latest Development?

It's a lesson worth repeating and remembering: "If he hadn’t failed, Thomas Edison might not have become America’s most well-known and prolific innovator." He failed when he followed traditional models but learned as a result to identify not just a seeming market need but something customers wanted enough to pay for. 

What's the Big Idea?

Lesson 1: Validate your assumptions about what customers will buy. Rather than letting failure destroy him, Edison learned the crucial need to understand customers (the job they are trying to get done and why). He decided, “I never want to build something that nobody wants to buy.”
Lesson 2: Iterate to discover what customers will buy. In developing a commercially viable light bulb, Edison went through thousands of prototypes before getting it right. Had he followed the traditional model of product-development model, his competitors would have beaten him by decades.