there is a very large social stigma attached to atheism in America

Except that a lot of well known Americans in the entertainment industry, which aims at the lower common denominators of American society, have come out by now as nonbelievers, along with ones in other countries who have some name recognition in the U.S. Their skepticism of religion doesn't seem to have hurt their ability to make a living in a competitive market. For some examples:

:http://en.wikipedia.org/wiki/List_of_atheists_in_film,_radio,_television_and_theater