Comment by fsckboy
>As for CDs, I don't see the rush; the ones that were properly made will likely outlast human civilization.
recordable CD-Rs or DVD-Rs do not last close to that long, and those are the ones that hold the only copies of certain bits (original versions of software, etc) that people are most interested in not losing.
manufactured CDs and DVDs hold commericial music and films that are for the most part not rare at all.
Yes, good distinction. Recordable media will most likely contain data an individual intended to save. But because it's recordable, the dyes and structures on the disc aren't as stable.
Long-lasting, good quality mastered optical media is probably mass produced and has many copies, including a distinct and potentially well-preserved source.
It's probably fair to say that a lot of mixtapes (mix CDs?) from the early 2000s are lost to dye issues...