DVDs don't last as long as we thought they would. Corrosion and delamination cause DVDs to be unplayable. DVD-CCA licensing practices and the Digital Millenium Copyright Act make it illegal to back up your media. This means you may need to re-purchase your DVDs possibly as soon as you would need to replace VHS tapes. The article says some movie rental stores are reporting only getting two or three rentals from a DVD before losing them to DVD rot.