Rewritable disks have a limited number of rewrites.

"CD-RW discs never gained the widespread popularity of CD-R, partly due to their higher per-unit price, lower recording and reading speeds, and compatibility issues with CD reading units, as well as between CD-RW formats of different speeds specifications.

Also, compared to other forms of rewritable media such as Zip drives, Jaz drives, Magneto-optical and flash memory based media, the CD-RW format uses the standard CD-ROM and CD-R file systems and storage strategies, which are inherently not suitable for repeated small-scale file additions and deletions, but rather for medium to large scale, single operation, cumulative archiving, thus making the use of CD-RW as a true removable disk impractical.

CD-RW also have a shorter rewriting cycles life (ca. 1000) compared to virtually all of the previously exposed types storage of media (typically well above 10000 or even 100000), something which however is less of a drawback considering that CD-RWs are usually written and erased in their totality, and not with repeated small scale changes, so normally wear leveling is not an issue."

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"Rewriteable (RW) media can have all the files deleted on a formatted disc, or information can be overwritten. The downside is CD-RW will fade to the point it isn't readable as the re-crystalized alloy de-crystalizes. Formatted CD-RWs seem to fade out faster than unformatted CD-RWs. People who assume RW media can be updated and reformatted many times just like a floppy disk eventually discover that their data has disappeared. And there are only so many times it can be completely erased and reused - it varies from disc to disc, and can vary with age and use."

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