Amazon runs all of the Amazon.com web servers on EC2 hosts (and has since 2010: https://www.youtube.com/watch?feature=player_detailpage&v=dxk8b9rSKOo#t=393s htt

Amazon runs all of the Amazon.com web servers on EC2 hosts (and has since 2010: https://www.youtube.com/watch?feature=player_detailpage&v=dxk8b9rSKOo#t=393s https://www.youtube.com/watch?feature=player_detailpage&...). They've just made sure that they have enough hosts in each of the other AZs to withstand an outage.