the unfortunate reality of digital backups is that they are all quite delicate.
CDRWs can lose data in as little as two years. sending a file to a huge online presence is tempting - after all, AOL is immortal, right?
magnetic media? well... there's magnets.
as far as i'm aware, the best and most durable/convenient method of archiving data that humans have yet devised is... the LP record.
weird, isn't it?
It's really odd, but you're right.
I'd say the next best thing is a physical magnetic HDD stored in a sealed firesafe in a temperature and humidity controlled firesafe. It wouldn't hurt to also put it on an SSD, a USB thumbdrive or five (hey, they're cheap!), CD-R's and DVD-R's just for the heck of it. Email it to several different websites/email addresses, and make note of what those websites/email addresses and passwords are on a sheet of paper placed in the firesafe. Also, print out the raw ASCII of the file, just in case.
I would also copy the data many times over on any given backup medium, provided there is space for it. That way, if you end up having a large some of money tied up in it, it would be worth it to get some forensics analysis done on the drive to recover the data if none of the files were intact. If the data is repetitious, then whoever is analyzing it can more quickly piece it back together. Just grab the good bits from here and there...
I wonder if there's anyone who provides some sort of digital storage that is 100% failsafe. I mean, they have backups of backups and more backups, several offsite locations for said backups that are both online and offline, and switch between the two. Backups on many different types of digital storage mediums. Printed backups. Backups in nuclear bunkers. Etc, etc.