Notes
1See “Bowker Reports Traditional U.S. Book Production Flat in 2009,” retrieved from http://www.bowker.com/index.php/press-releases/616-bowker-reports-traditional-us-book-production-flat-in-2009
3See Alicia Ashby, “Zynga Revenue Estimated at $50M Per Month,” retrieved from http://www.engagedigital.com/2010/05/14/zynga-revenue-estimated-at-50m-per-month