Most likely usage (my opinion, ymmv)
Electronic Data Management System
We have such an animal at work and it involves storage of documents, mainly. It is our archival storage, using both hard drives and optical discs. Old documents were scanned from paper or micro-fiche, newer documents are stored in TIFF or PDF format. Backups of some Oracle Tables are also kept there.
All are indexed and viewable through a CIMAGE interface. There are many vendors.
I think our vendor was chosen primarily because of the long-term archival capabilites of the laser-disc storage.
This is for a nuclear power plant, and we are required to store an absolute butt-load of documents for the "life of the plant."
Some are already 30 years old and we may have another 40 years of operation, plus the time it takes to decommission.