Did you ever wonder which are the biggest storage companies in terms of revenue? Across all segments and technologies, just sheer size?
Well, here's that list and surprisingly, the "component" companies like Seagate, WD or SanDisk have much higher revenues than the "system" vendors like Netapp and HP.
With the notable exception of EMC obviously.
However, there are signs that the hard-disk vendors might be loosing some of their share of the storage industry in the next couple years: The industry is on the verge of completely redefining storage tiers with the advent of affordable SSD technology (for primary, active data), high capacity HDDs (for backup and inactive data) and huge capacity tape (for archive and last-resort backup data).
Even though we had some bad news about "sanitization" of SSDs published recently. So when moving to an all-SSD storage environment, clients may well want to think about encrypting that data first!