Now wait a minuite! Sales of iPhone's should have no impact at all on the USA GDP, it is not a USA product.
Definition of 'Gross Domestic Product - GDP'
The monetary value of all the finished goods and services produced within a country's borders in a specific time period, though GDP is usually calculated on an annual basis. It includes all of private and public consumption, government outlays, investments and exports less imports that occur within a defined territory.