Are there really 50 million Cocoa Touch Users out there?

Or : Do you own more than one iphone/iPod in your family? Between my wife, my son and I, we have 6 different devices (I have a lot, because of tests). If you have an iPhone, you want your wife/husband to have one too, but you don't want to pay twice for apps, so you easily manage to share them among your different devices. I'd say there are roughly 30 millions discrete buying users out there, which is less than the 50 we heard about last night. That's still a lot of people (more thant the workforce in France, for example).