Money. You buy a second set of instances in a different availability zone and failover to it in case of problems. You buy a second datacenter at a different ISP

Money. You buy a second set of instances in a different availability zone and failover to it in case of problems. You buy a second datacenter at a different ISP, keep it in sync and failover to it when your primary fails. Eventually you architect your application to distribute load over multiple facilities and to become resilient against component failure. Until then: You do nothing, grab a beer, relax and wait as the amazon guys sweat their asses off to fix it. You pat yourself on the back because it is not your ass in the trenches right now. On top of that you have the perfect excuse for the followup blog-post.