As Scientific American notes, Amazon learns about its customers through Alexa-gathered data. During the 2017 holiday season, the company said it indicated that the martini and the Manhattan were the most-requested cocktails, "Jingle Bells" was the most common song, and the most common person called in the US was "mom."
Data like this helps Amazon market products on its shopping site, and it's possible the company could collect even more intelligence by replicating the strategy on street corners. This could also create some concerns about privacy.