Visitors embrace the online retailer’s move into the physical world – even if the brick-and-mortar store serves in large part as an ad for Amazon Prime

Drop in for a book. Walk out with a smart watch.

Shopping in one of Amazon’s brand-new, three-dimensional bookstores affords visitors the opportunity to buy many things that aren’t books. A hands-free sous vide, for example. Or a tablet computer. Or a smart speaker equipped with Amazon’s “Alexa” virtual butler app.

At a grand opening Thursday for Amazon’s first bookstore in New York City, the mystery in the air was why a company that had changed the world by taking retail sales online would reverse direction and move into brick-and-mortar. The New York location is the seventh Amazon bookstore to open nationally since 2015, with six additional stores planned to open by the end of the year.