While consumers are using smart home speakers to listen to music and answer questions, they’re also increasingly using them to buy things.

Voice shopping is already a $2 billion business and projected to grow to $40 billion within four years.

Online retail giant Amazon is projected to dominate the home speaker market, which will grow from 13% to 55% of homes, according to a study comprising a survey of 1,500 smart speaker owners conducted by OC&C Strategy Consultants.

Three tech giants lead the virtual assistant AI space in the U.S. Amazon’s Echo has 10% penetration, Google’s Home 4% and Microsoft’s Cortana 2%. Apple just recently launched its high-end HomePod smart speaker.

There are some twists in voice commerce, however:

by Chuck Martin , Staff Writer, March 2, 2018

However, Amazon still has the upper hand. A large majority (85%) of consumers select the products Amazon suggests.

That Alexa is one smart voice retailer.