When the shortage occurs, some customers are willing to wait for back order and others would turn to buy from other sellers.
In a conference call with analysts, Timothy D. Cook, Apple's chief executive, said that demand for the new iPhone was "extremely robust" and that the company had a significant number of back orders for it.
With its quick launch in Japan, the handheld sold 40,000 units in its first two days, 90,000 within a month, and the number of back orders for the system was over 600,000.
Supplies have been low from the get-go, and though Fuji has pledged to produce more in 2013, it will take months for back-orders to be filled.
Nevertheless, Amazon.com sold out its entire inventory of the devices as soon as the product went on sale, requiring numerous customers to wait for months on back orders.
This was widely expected to cause shortages in worldwide markets for computer memory chips, with back orders piling up until Taiwan's production flow could return to normal.
They said they would also hold back orders for a half-dozen planes in the sixth batch if Lockheed could not do the retrofit work faster.
He has paused his cheerleading only once before — during the dot-com crash more than a decade ago, when Cisco was unprepared for customers sharply cutting back orders.
Patrick Yap, manager of B Chemist, a department store and pharmacy in Manhattan that sells toys, said he has more than 700 back orders for Webkinz.
The company now has back orders for over 50,000 units, worth about £100m, and is hard at work equipping a new factory in Sussex which will begin production in late 2009.
Cipro is on back order for a month everywhere.
