Bezos has built a $174 billion empire by continually churning out new products with mass consumer appeal, from e-reader tablets to streaming-only TV shows to, soon, goods delivered by drones. Not all his investments have paid off: Amazon’s much-hyped Fire Phone, which made its debut last summer, was a flop. Yet the visionary CEO not only created his diversified behemoth from scratch but turned e-commerce from a fanciful idea into a globe-changing practice.