I used to track AAPL when I was interning at a financial services firm last summer, and I can assure you that their profit margin is around 20%. Since AAPL is publicly traded, this information is publicly available so anyone can verify it. I'm not sure where you get the idea that their profit margin is 70%.
According to Yahoo Finance (which is a pretty good resource for non-professionals), the profit margin is currently 21%.
According to Yahoo Finance (which is a pretty good resource for non-professionals), the profit margin is currently 21%.
http://finance.yahoo.com/q/ks?s=AAPL+Key+Statistics