It is designed for data that is infrequently accessed, yet important to retain for future reference and for which retrieval times of several hours are suitable.

FORBES: Web Services To Drive Future Growth For Amazon

Amazon Glacier is designed for data that is infrequently accessed, yet still important to retain for future reference, and for which retrieval times of several hours are suitable.

ENGADGET: Amazon Q3 2012 earnings: $13.18 billion revenue, net loss of $274 million

As effective as filing was to the retrieval of any emails for reference purposes, it was even faster to just use a simple search in Gmail.

FORBES: Are You A Filer Or Piler?