Clients DVD-R's Lifespans

OSTA says that the average lifespan of a burned CD-R and CD-RW is about 5-10 years. DVD-R's likely have a similar lifespan.

So you have a few options when it comes to storing your digital data:
Optical Media you burn.
Professionally made Optical Media.
Tape Backup
Mechanical Hard Drives
Solid State Hard Drives
RAIDs
Offsite RAIDs and Vaults
and now DiamonDiscs.

Cranberry says they only last 2-5 years so they've come up with an optical burnable disc that they claim lasts 1000 years. Yes, one thousand.

How's it work?

A Cranberry DiamonDisc is a DVD made of high tech stone.
Memories carved on a DiamonDisc will last as long as the pyramids. No reflective surface. No ink layer. No fading. Problem solved. The Library of Congress is studying our technology for storage of the national archives. It’s the only solution for permanent, digital storage.

The hitch is you have to buy an expensive ($5000.00) proprietary burner or send them your data and have them burn the discs for you. Their product page is here.

One thing I like on their site:

We need your money. How's that for transparency? The technology behind the DiamonDisc is so expensive that we cannot make much money selling you the DVD. We need you to subscribe to the DVD vault service so that we can pay the bills.