Amazon helped kill bookstore chains, and now it’s becoming one.

The company has been opening physical bookstores in cities like Seattle, San Diego and Chicago since 2015. Last week, it opened its seventh bookstore in an upscale mall in New York City. In an ironic twist, Amazon’s store is one floor up from a former Borders store, the bookstore outlet that went belly up in 2011 after failing to compete with Amazon.

Like many aspects of the notoriously secretive Amazon, it’s still unclear what the company is trying to get out of its take on the bookstore. Jeff Bezos’s company has made a habit of pursuing projects that seem baffling to outsiders but more than pay off. Few people anticipated Amazon would become a significant distributor of TV shows and movies, or reorder corporate technology with pay-by-the-hour computing at its Amazon Web Services division.

While the company deserves the benefit of the doubt, running stores is replete with annoyances large and small. And the potential financial payoff in books doesn’t seem worth the trouble — unless Bezos has a strategy up his sleeve to use his bookstores for other purposes, such as test labs for new technologies for physical stores.

To step back a bit, Amazon is tiptoeing into bricks-and-mortar retail in a few different ways. In addition to its handful of bookstores — and more are coming — Amazon is also working on several store concepts for groceries and prepared foods. The company is testing a highly automated convenience store in its hometown of Seattle, and Amazon is trying spots for people to drive in and pick up groceries they ordered online. Full-fledged Amazon supermarkets are likely coming next.

It’s sensible for Amazon to turn to physical food locations in its quest for a bigger chunk of shoppers’ budgets. In the U.S., buying groceries accounts for…