$9 million By one estimate Source http://www.joshuakennon.com/how-much...united-states/ http://www.joshuakennon.com/how-much...united-states/ By one estimate http://www.joshuakennon.com/how-much...united-states/ one author http://www.joshuakennon.com/how-much...united-states/ $9 million top earners http://www.joshuakennon.com/how-much...united-states/ http://www.joshuakennon.com/how-much...united-states/ http://www.joshuakennon.com/how-much...united-states/ $9 million $9 million http://www.joshuakennon.com/how-much...united-states/