NEW YORK (AP) - This year, holiday stress may take on a whole new meaning for online retailers.
Amazon, Walmart and others have promised to deliver more of their orders within 24 hours of customers clicking on "Buy."
The coming weeks will be the first test of whether they can make that happen during the busy holiday shopping season, when onslaughts of orders and bad weather can lay waste to even the best delivery plans.
It's an expensive feat that requires not just additional planes and vehicles, but more workers and reams of data to help retailers prepare and predict what shoppers may buy.
And the stakes to deliver on time are high. A late package can damage a retailer's reputation, since shoppers tend to blame them, even if the late arrival is the fault of the delivery company.