Actually, AWS has more than 10 data centers that make up US-East-1. This was mentioned in the post-mortem published last week. Availability zones in US-East-1

Actually, AWS has more than 10 data centers that make up US-East-1. This was mentioned in the post-mortem published last week. Availability zones in US-East-1 are at least one data center, but may be multiple facilities in geographic proximity.