I think it's supposed to be a dynamic solution. ie. They have a standard capacity for 1 million transactions a minute, and when demand exceeds that, Amazon scales up to 2 million transactions a minute. Then when demand dies down, it reverts back to the 1 million standard capacity.How does scaling up the service differ from increasing server capacity?
Dunno how it'd work, short of renting capacity from another server network. I can't Google any details so don't know the ins and outs, but the reasoning is sound.