You don't lose a day of sales, customers come back when the site is up again.
You have to realize when software companies tell the world they should rely on their works, they world will do so. And once that occurs, the responsibility is all on the software companies to meet the expectations they built in people!
It's mad that this industry works so hard to claim the trust of millions of people, then shirks it as soon as it's convenient.
It's shameful.