pg, or someone else from HN... Could you please edit this title for accuracy? Maybe, "Poorly designed sites taken out because of problems in one Amazon availability zone."
For many sites, a single server in a single zone (e.g., a non redundant server, an instance, a slice, a VM, whatever) is the right decision for ROI.
For many sites, the money spent on redundancy could be better spent on, say, Google Adwords, until they're big enough that a couple hours downtime has irreplaceable costs higher than the added costs of redundancy (dev, hosting, admin) for a year.
-The right to not have your traffic limited, and controlled by ISP
-The right to purchase a non DRM "file" and use it on your phone, computer, etc free of burned from some company
-Ability to install what ever you want on your $600+ device
*Edit for: formatting, and additional thought.