Technical developments and improvements in the manufacturing of flash storage allow one to save a large amount of data in the smallest of spaces. A large advantage over the common practice of saving to optical disc is the very short access time of flash. USB sticks play a large role in the flash memory market, as they provide easy handling, resistance against wear and tear, and compact dimensions. In many ways, they are the ideal mobile storage medium.
Finally, the low price of this memory medium contributes to its widespread use. Eight dollars for a USB stick with a capacity of 1 GB is not uncommon.
Data Theft, USB, And You
USB sticks can become a threat for companies however, because of how ubiquitous they are and how easy they are to lose. Regular USB sticks, along with MP3 players and cell phones, can be connected to the USB port of any computer, which identifies them as common hard drives. So nothing stands in the way of copying sensitive data onto these media, unless suitable precautions are taken to prevent it.

Simple point is, some companies actually care about making the jobs of their employees easier, and if that means supplying a $10 USB drive (that they can confiscate at any time) they make that effort. Most companies, however, spend as little as possible to aid their employees and don't understand why their productivety suffers. Their IT departments are also people who have simply undergone a multi-day training session, and are only there to look confused and package the broken components and ship them back to HP or Dell, they don't understand nor care that someone can copy sensitive information to a USB drive and walk out the door with it.
While it's interesting to see a product like this, the prohibitive cost and complexity will never see a vast market segment. Too many large companies simply care more about the bottom line than anything else.
A really reliable and easy to use secure USB drive.