Amazon's Echo Dot, it's Alexa powered mini speaker was the biggest selling item on Amazon over the Xmas period - Selling an estimated 10 million+ units during the holiday period.

Amazons Echo Dot

Amazingly (lot of A's in this article) the Amazon Fire Stick (powered with Alexa) was the number two best selling item.

Sonos One with Alexa Technology

Seems everybody is getting into the voice control game, even my dear Mum got a Sonos One with built in Alexa for Xmas.  When my Nan get's one I can rest assured that it's finally thoroughly and absolutely mainstream.