Indeed, I think of those claims as a mixture of optimism, wishful thinking, and marketing drivel. How can someone claim that it lasts for 100 years, unless you

Indeed, I think of those claims as a mixture of optimism, wishful thinking, and marketing drivel. How can someone claim that it lasts for 100 years, unless you have tested that claim by waiting 100 years and then verifying that the data is still there ? After many years of experience with CD-R and DVD-R, one can say that those disks are good for at least 3 years. But we can only say that because lots of people have successfully read CD-Rs that were 3 years old. Also, they can sell those "100-year" disks with these claims, and when customers lose data after 5-6 years, the company just says "oh that's too bad, maybe you stored them where the temperature fluctuated by more than +/- 0.1 degrees Celsius ?" and you have no recourse other than not giving them more of your money in the future.