Apple's effect on the U.S. economy (vs competitors)

Hi all. Are there any data points to show how big of an impact Apple has on the U.S. economy? Logic alone tells me that Apple probably has a bigger positive impact on the American economy than its competitors (particularly foreign ones), but I am unable to find concrete data to corroborate my hypothesis. In fact I've encountered people who actually dispute that notion:

http://gizmodo.com/5873806/samsungs...ce-recognition-game?comment=45852293#comments

Any assistance is appreciated. Thanks.