An unallocated item/product inventory is maintained in each of a plurality of delivery vehicles traversing service routes within a delivery service area. Upon receipt of an order for delivery of an item/product that may be selected from the item/product inventory maintained within a delivery vehicle and that is to be delivered to a destination location within the delivery service area, a delivery vehicle driver is instructed to deliver an item/product selected from the item/product inventory located on the delivery vehicle during the corresponding service route on the same day that the order was placed. A delivery label for the item/product is printed, and the delivery vehicle driver secures the printed delivery label to an item/product selected from the unallocated item/product inventory, and delivers the item/product to the destination location on the same day the order was placed.