James S. Heller, The Librarian's Copyright Companion (2012)
“ To justify the effort and expense of digital preservation, the works preserved will typically be unique, rare, or, in any event, out-of-commerce, and the library’s activities therefore will not be mere substitutes for acquisition of a new digital copy of the work. Works in obscure, near-obsolete formats present access challenges as well as preservation ones, but the same fair use rationales will apply. Works trapped in decaying and increasingly obscure formats will disappear completely without diligent work from librarians to migrate them to usable formats. ”
