Many of the world’s largest technology companies have spent the last five years searching in vain for the holy grail, a machine to succeed the smartphone as the next must-have gadget. They have made digital watches and fitness trackers, all manner of computerized glasses and goggles, and more doodads to plug into your TV than there are shows to watch on it.
Yet at the moment, the most promising candidate for the Next Great Gadget isn’t made by Apple, Google, Facebook or Microsoft. Instead, it is the Echo, a screenless, voice-controlled household computer built by Amazon — a company whose last big foray into consumer electronics, the Fire Phone, was a humiliating flop.
