Microsoft's Cortana Mistake: Relying on Windows

Amazon.com Inc. AMZN 1.24% introduced its Alexa digital assistant seven months after Cortana's launch, but its Echo and sibling devices now control two-thirds of the U.S. smart-speaker market, according to research firm eMarketer. The market share of devices using Cortana isn't large enough to be listed in eMarketer's tally. Microsoft's effort to turn Cortana into a viable competitor, while voice computing is still in its early days, is bigger than just the market for smart speakers that sit on kitchen counters checking the weather. It is an opportunity to lead in the next big advance in computing, in which people use their voices rather than a keyboard and mouse. Companies that master so-called conversational computing will have an edge in the emerging business just as Windows gave Microsoft an advantage in the PC era, analysts say.