Brownlee : Unveiling of a new Apple is another sign of Apple 's competitive advantage . He says Apple does more than innovate ; it controls supply chain and freezes out competitors . Then there 's a MacBook Air . Apple 's products can then be sold at extraordinarily high profit margins , he says . John Brownlee : MacBook has a virtual `` time machine '' with which it 's able to stay at least a year .
Brownlee : Unveiling of a new Apple is another sign of Apple 's competitive advantage . He says Apple does more than innovate ; it controls supply chain and freezes out competitors . Apple 's products can then be sold at extraordinarily high profit margins , he says . John Brownlee : MacBook has a virtual `` time machine '' with which it 's able to stay at least a year .