It looks that they are losing $2,054,794 per hour of downtime [1].
[1] http://www.dailymail.co.uk/sciencetech/article-2989656/Apple...
[1] http://www.dailymail.co.uk/sciencetech/article-2989656/Apple...
I've heard from various third-party developers that store downtimes (of reasonable lengths) tend to be followed by corresponding sales spikes, so that ultimately nothing is lost. I have no idea if that applies here, but it's reasonable to think it would at least partially.