Digital objects, whether born-digital or digitized, (as well as," newer" analog media), are more fragile than paper-based resources.
There's a variety of concerns:
Corrado, E.M. & Moulaion, H.L. (2014). Digital preservation for libraries, archives, & museums. Lanham, MD: Rowman & Littlefield.
Library of Congress. Personal digital archiving series: How long will digital storage media last? Retrieved from http://www.digitalpreservation.gov/personalarchiving/documents/media_durability.pdf
Library of Congress. Personal archiving: Preserving your digital memories. Retrieved from http://www.digitalpreservation.gov/personalarchiving/
Library of Congress. (2013, July 24). Sustainability of digital formats: planning for Library of Congress collections. Retrieved from http://www.digitalpreservation.gov/formats/index.shtml
* National Digital Stewardship Alliance. NDSA levels of preservation. Retrieved from http://www.digitalpreservation.gov/ndsa/activities/levels.html
Cornell University Library. Chamber of horrors: Obsolete and endangered media. Retrieved from http://www.dpworkshop.org/dpm-eng/oldmedia/chamber.html
Cornell University Library. Digital preservation management: Implementing short-term strategies for long-term problems. Retrieved from http://www.dpworkshop.org/
UMass Amherst Libraries. (2012, May 18). Preserving your digital materials. Retrieved from http://www.library.umass.edu/services/services-for-faculty/preserving-your-digital-materials/