A customer at a retail store picks a bottle of shampoo off the shelf, heads to the cashier, and pays for the product. The radio frequency identification (RFID) tag on the item sends a notice to the store's network -- alerting it that inventory has been reduced. The network automatically communicates with computers at the shipping center of the shampoo maker, which triggers a shipping notice that more shampoo is on the way to replenish the dwindling stocks of Head and Shoulders.