Amazon's bookstores aren't just for selling books, according to CFO Brian Olsavsky

Amazon now has three brick-and-mortar bookstores in Seattle, San Diego, and Portland, with plans to open five more this year.

Although Amazon's bookstores offer a completely different shopping experience, the move was a bit of a head-scratcher, given how a lot of the national chains have shut down their bookstores in recent years.

But according to Amazon CFO Brian Olsavsky, the bookstores are meant to be much more than just a place to sell books. They're also a great way to showcase Amazon's hardware devices and drive up their sales.

"We think bookstores, for instance, are a great way for customers to engage with our devices, to see them, touch and play with them, and become fans, so we see a lot of value in that," Olsavsky said during the earnings call on Thursday.

Olsavsky added that Amazon is continuing to test and innovate with the bookstores, and that the company's learning a lot about the benefits of having a physical presence. It's also why Amazon has been ramping up its pop-up stores and college pick-up spots in recent months, he said.

Although Olsavsky didn't share more details, Amazon's devices seem to be partly benefiting from the bookstores: Amazon's Echo devices saw their holiday sales jump 9-times compared to last year, while Amazon hardware devices, including the Echo, Fire TV, and Fire Tablet, had the best-ever holiday sales in 2016.