Amazon Glacier

Amazon recently introduced Glacier, a cloud data archival service. Based on James Hamilton's post, is presumably built on a large, shared, tape infrastructure. With the addition of this service, Amazon now provides a very compelling set of storage services to suit a whole variety of application needs.

Service	Purpose	Pricing (As of August 2012)
ElastiCache	Memcached service	9 cents/hour for 1.7GB node ( = 3800 cents/GB-month, approx.)
DynamoDB	Low latency, guaranteed throughput, indexed, SSD-based NoSQL store	100 cents/GB-month
SimpleDB	Older, more complex NoSQL store	25 cents/GB-month
EC2 Local Storage	Instance-local storage	Approx 36 cents/GB-month
EBS	Reliable block store	10 cents/GB-month
S3	Cross-datacenter durable storage	12.5 cents/GB-month or, for reduced redundancy, 9.3 cents/GB-month
Glacier	Archival storage	1 cent/GB-month

Each service has a different pricing structure based on the I/O requests you subject it to, and different guarantees about how long the requests might take. But if you look at it purely from a storage cost standpoint, you have a clear idea of how much it costs a developer to keep a piece of data in memory, on SSDs, on local on spinning disks, in-datacenter-redundant disks, cross-datacenter-redundant disks, or on tape!