came up with the Zip Drive
back in 1994. It was an external drive that could store 100MB on a removeable disk that was a little bulkier than a 3.5" floppy disk
The drive was released at an original retail price of around $200 and the disks were around $20 each. $20 for 100MB of removeable storage in 1994 was not bad; Syquest cartridges were much more expensive. For this reason, the Zip Drive caught on fairly quickly.
Zip drives were most popular in the Apple Macintosh community initially; afterall, the first zip drives were only available in SCSI and parallel port versions, and the parallel port version was godawful slow. Add to this the fact that Macs had SCSI built in at the time, and you had a winner for the Mac market. People creating bootable zip disks with MacOS 7.5 on them for system recovery was a common ocurrence.
Unlike other mass storage systems, Zip drives have heads that actually touch the media, so they have more in common with floppy drives than removeable hard disks like what Syquest had at the time. This allowed media to be relatively inexpensive, but this came at a cost in reliability; Zip Drives were extremely failure-prone. Sometimes the drive would damage a zip disk in such a way such that the next drive you put the disk in would be destroyed. This was known as the click of death and it seriously tarnished the drive's reputation. Heads touching the media, along with the media's thin, floppy-disk like nature, also contributed to the drive's slowness; the disk couldn't be spun very fast so users had to contend with 1MB/sec transfer rates and lousy seek time.
For those seeking higher performance and capacity, Iomega also had the Jaz Drive, which used 1GB removeable disks with hard-drive style platters. At $100 a disk, though, this was way too expensive for some.
Iomega eventually improved the Zip mechanism so the click of death was less likely, and eventually released 250MB, and more recently 750MB versions of the technology. Their market dominance is no longer what it once was, though; with dozens of removeable media solutions in the market, including the becoming-ubiquitous DVD+-RW, DVD-RAM, and CD-RW formats with much higher capacity, Iomega's days in the removeable media market may be numbered.