Thanks very much for the insight - what you are saying actually makes a lot of sense in the context of systems inside the AWS ecosystem. After all, they need to archive data as well. Also - my 140 container example w/Iron Mountain was Pre-versioning and always-online differential backups. We basically had a complex tower-of-hanoi that let us recover data from a week, a month, six months, and then every year (going back seven years) from all of our servers. (And, by Year seven, when we started rotating some of the old tapes back in - they were a generation older than any of our existing tape drives. :-)

Clearly, with on-line differential backups - you might be able to do things more intelligently.

I'm already looking forward to using Glacier, but, for the forseeable future, it looks like the "High End" archiving will be owned by Tape. And, just as Glacier will (eventually) make sense for >100 Terabyte Archives, I suspect Tape Density will increase, and then "High End" archiving will be measured in Petabytes.

Thanks again.