Amazon says it's cutting its Prime 2-day shipping guarantee to just one day

AP/Patrick Semansky

Amazon CFO Brian Olsavsky announced on Amazon's first-quarter 2019 earnings call that it is working on turning its Prime two-day shipping guarantee into a one-day shipping offering.

Olsavsky called the move a "significant step" on the call.

The initiative will take time to come to fruition, he cautioned. The company said it will take on $800 million in additional expenses in the upcoming quarter.

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