[modeless]

I don’t think you can look at the average hourly revenue of the online store, look at how long it was down and calculate Apple’s revenue loss from that.

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.