Is the AppStore Really a Cash-Machine for Apple?

While Apple heavily communicated about the billionth application downloaded on the AppStore, some analysts tried to evaluate how much cash this iPhone-dedicated online software shop might have generated for Apple. Indeed, it includes both free and fee-based applications, and despite this achievement of having already more than one billion iPhone app downloaded, it might have brought Apple "only" 70 to 160 millions USD (income). If one removes the infrastructure/hardware/software investments associated with updating/upgrading the iTunes Store (as the AppStore is nothing else than a category of the iTunes Store), Apple's margin on sales of 30%, at the end, it might only bring 20 to 45 millions of the company. 
Of course some investors might think it is not enough, or not the golden-eggs chicken expected. However, it might also only be the beginning and/or the most important point might not be linked to generate a cash flow now, but rather attract more and more people to the AppStore by making the iPhone a mobile phone for all. Apple might also push some developers to further increase the price of their applications in order to increase its income without modifying its margin on sales.