Why does Apple always take their entire online store down whenever they do product updates? It must cost them hundreds of thousands if not millions of dollars in lost sales every time.
Only the super-rich can afford to go impulse buying in Apple’s online store (or any store selling expensive stuff).
Of course not. But neither can you say that 100% of people will come back after the store turns them away. There is undoubtedly a cost to store downtime; the only question is how much. On a high traffic store like Apple's, even a small percentage of lost customers is a large amount of money lost.