Magneto-Optical storage has many advantages over other types of removable media:

• Media life is at least 30 years, which greatly exceeds the life of magnetic media like floppy disks, Zip and Jaz disks. Some manufacturers quote media life of 50 or even 100 years. Data can be rewritten at least a million times, and read at least 10 million times; some manufacturers quote figures ten times this. This figure also exceeds that for magnetic media.
• There is no physical contact between disk surface and drive head, so there is no possibility of data loss through a head crash.
• MO drives are backwardly compatible, which means that if you upgrade your drive in the future, you will be able to read and write all your existing disks on the new drive.
• MO disks are not susceptible to magnetic fields.
• If, for example, you spill a cup of coffee on an MO disk, you can clean the disk surface and continue to use the disk. Cleaning kits are available for both MO drives and disks. Disk cleaning kits are very cheap.
• MO disks are simple in construction, unlike some other kinds of removable media which may contain moving parts. This is another reason why MO offers greater reliability than magnetic media.
• MO disks are available in several different capacities, which vary in price. Cost per megabyte is lower than all other kinds of random access removable media.
• Unlike Zip, Jaz, SyQuest etc., MO drives and disks are not proprietary, and they are made by many companies. The disks are covered by various international standards. So you will not be stuck if your drive manufacturer goes bust, as happened recently to SyQuest.
• Compared to other forms of optical storage, there are no restrictions on writing and rewriting data to MO disks, unlike CD-R or CD-RW. Also unlike CD-R & CD-RW, since the disk itself is protected by a plastic casing, there is no danger of data corruption due to the disk getting scratched.
• MO drives normally automatically verify written data to guarantee data integrity. There is no such verification with CD-R and CD-RW, so to be assured that the data has been written properly when using these, you would need to manually compare all copied files.
• Magneto-optical technology is well-proven. I believe the first 128MB 3½" MO drives were available in 1992. 640MB drives have been available since 1996. Originally MO was largely restricted to professional use due to high drive cost, but over the past couple of years this situation has changed.
• MO disks are convenient, compact and easy to use. 3½" MO disks are the same size as two floppy disks stacked on top of each other. They have a write-protect tab which works just like a floppy disk's.

This quote is taken from an information sheet about Philips' 640MB MO drive: "ISO standard magneto optical disks offer virtually unlimited rewritability and are ideally suited whenever extraordinary data reliability is required. With its high resistance against external magnetic fields and the impossibility of 'head crashes' magneto optical storage technology is the better choice in terms of safety and reliability."