The common forms of digital storage are either hard drives or CD/DVD. Hard drives on average rarely last 10 years, more realistic estimates say 5 years. The lifespan of CD/DVD's will vary depending on the quality of the blank disc and the burning speed..........ie: the quality of the dyes used in the disc's manufacture and the intensity of the "burn" into those dyes. How long before the dyes suffer degradation is anyones' guess..........I've seen a few burnt CD's become useless within a matter of months. For the best chance of longevity, the general concensus is to burn at a quarter of the disc's rated burn speed. A purchased disc (either audio or vision) is not burnt, they are essentially "pressed" similar to a vinyl record, consequently, short of physical damage to the surface, there's not much that can cause degradation..........at least nothing has become evident since their introduction in the early '80's.
On the other hand, "information" stored on analogue formats (tape or film) can, if stored correctly, last for many, many years. Claims of 100 years are not too far fetched if one considers the number of old films that are in existance whereas, as one museum archivast said......"digital information will last forever or 5 years...........whichever comes first".
