I think the majority of the revenue comes from iPads, iPhones and iPod Touch's.
Those devices probably cost less than $75 to $150 to build. The Mac revenue has been level or declining for some years. Much of it because of their smaller (but still quite adequate) profit margin but also because of fairly high longevity (fewer replacement sales). On the other hand, those other devices have been helpful to show what computing on a Mac might be like and has helped sales. And, the market for full-sized computers is becoming ever more saturated, in my opinion. And still clearly dominated by the Windows OS.
More and more people just see all computers as tools, not something that could be enjoyable to use. That and the fear of change keeps most of the world on Windows PCs and I don't see much of a change in the future.
