This could be a better method than microfilming or photocopying old brittle books, now deteriorating due to the acidic paper on which they were printed. Such paper was manufactured from around 1850 and a hundred years on. Right now printed matter from a whole century is being silently destroyed on library shelves worldwide, a loss that could be far worse than the burning of the library in Alexandria. So, let us discuss vulnerability. H. G. Wells was aware of the importance of not putting all the eggs in the same basket.
Most people know that computer technology develops very fast.
Approximately every five years the industry presents a totally new generation of computers, with new processors, which need new operating systems and new software. We already have great difficulty with other media. Suppose somebody gives you a Betamax video from the 70's. Many of us also have audio tapes on large 7-inch reels at home, but we only have cassette decks in our stereo systems. Not many national archives and libraries have a strategy for dealing with electronically published works.