I have to agree with the parent about the marketing aspect and add that many people are moving from physical media to digital content. Music, movies, etc. The wheels of progress move slowly but eventually you'll be downloading new movies instead of buying disks. We've gotten to the point where even email providers are persuading people not to delete their correspondence anymore. The whole process is cyclic. Hard drive manufacturers improve hard disk capacities and in turn,
new technology can be implemented. For example, I work in the CCTV field. Larger hard drives means I can have more recorded content, higher framerates and/or higher quality recorded content. There are also great new technologies that rely on having a large amount of space available.