That report is highly misleading. Year-over-year drive sales were down 21% in the September quarter and in the December quarter of 2010 drive shipments were 168 M units versus 150-155 M expected for this quarter.
And what is the avg drive capacity in 2010 vs 2012 (smaller drives, smaller margins, smaller gross margin dollars)?
What were Gross margins is 2010 vs 2012?
Finally, how is it that an industry can ship fewer units yet still sizable profits?
Fixating upon TAM will lead to the wrong conclusion regarding how much money the HDD industry can make. It also shows you either don't know the HDD industry or don't care (just a short playing headlines).