DVD Rot, or Not?:
"The recent Associated Press story about insidious, disc-devouring 'rot' wasn't the first to hit the mainstream press. Major news outlets Worldwide have for years been publishing sensational reports that up to 20 percent of all mass-produced CDs and DVD-Video discs were slowly destroying themselves. But when an alarmed DVD industry investigated whether the problem was indeed as catastrophic as it appeared, it turned out that most reported incidents had actually been caused by improper disc handling and storage. Despite the latest round of headlines, true 'DVD Rot' today appears to be exceedingly rare. Users themselves are the greatest threat to the longevity of their DVD collections.

Most people think of DVDs as little more than high-capacity CDs, but though the two are very similar, DVDs have vulnerabilities that require particular care in their handling, storage, and cleaning. But with a bit of knowledge and effort, nearly all damage to DVDs can be prevented.…"

http://www.pcmag.com/print_article/0,1761,a=126783,00.asp