Close to the center of Shenzhen is a massive market called Huaqiangbei, which is dedicated to selling electronic parts; it’s where you can purchase wifi devices, sensors, a circuit board, or 100,000 circuit boards. The city is full of incubators and consultants who specialize in hardware production. This cluster of manufacturing expertise is one reason the Economist declared Shenzhen the best place in the world for a hardware innovator to be.
Apple decided that the first iPhone would be manufactured in Shenzhen by a Taiwanese company called Foxconn. Shenzhen is now totally dominant in mobile production, turning out not just iPhones but also Android devices for the whole world. And the spillover effects of these innovations have made it a lot easier to develop new products. Electronic components that used to cost tens of thousands of dollars (if they could be bought at all) may now only cost a few dollars, allowing more inventors to prototype and produce.
I first heard of Shenzhen when I was working with Griffin Technology in Nashville many years ago. Even then, the guys at Griffin knew it was going to be a big deal eventually.