First the money was earning!
Second, investment in outside products is always available.
Third, investment in "content."
4th, investment in internal software development.
My own feelings about share buy back is that it is for political reasons. Keeping the shareholders happy.
STEVE JOBS DIDN'T THINK HE HAD TO DEIGN TO INDULGE IN THIS KIND OF PAP.
... but Steve is gone, isn't he, and there hangs the tale -- an inevitable decline.