NPD: 40% of freemium players pay for in-game upgrades: http://www.gamasutra.com/view/news/169040/NPD_40_of_freemium_players_pay_for_ingame_upgrades.php
Ensemble Studios: From Beginning to End, An Excerpt from Gamers at Work:
http://www.gamasutra.com/view/feature/168995/ensemble_studios_from_beginning_.php
Finding Out What They Think: A Rough Primer To User Research, Part 1: http://www.gamasutra.com/view/feature/169069/finding_out_what_they_think_a_.php
From the editor: Valve’s handbook and the trust phenomenon:
Postmortem: Housemarque’s Outland: http://www.gamasutra.com/view/feature/169282/postmortem_housemarques_outland.php
Inspire People to Change: http://www.greatleadershipbydan.com/2012/04/inspire-people-to-change.html
Managing the Game 