VCR as backup device?

In a technological coincidence that seems a bit odd, a British company, Danmere has announced that they have created technology that will allow a PC user who has Windows 3.1 or later to backup to a VCR, storing somewhere in the region of 4GB. This seems totally logical, but I find it odd no one else has done it. Does anyone know of any problems with doing this? And how susceptible to loss of data would the tapes be?