Delivery firms can save lots of money by sending a batch of parcels to a single place, where delivery is guaranteed, so they are naturally keen to provide the service.

ECONOMIST: Package pick-up services are set to prosper

Now, when inventories fall below a certain level, the checkout scanners instantly order a new batch based on historical demand and delivery time.

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In the first hour, the first batch of iPhone 5 smartphones were sold out, pushing back delivery times from September 21 to as far as early October.

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He'll examine one batch from each supplier and if clear, he'll sign off and they're good for delivery.

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