Brian Lowry hits the nail firmly on the head with his piece at Variety on how self-selecting groups skew impressions of whether or not a genre film will do well or not . . . actually, on how self-selecting groups for anything can skew results . . . see his insightful article at http://www.variety.com/article/VR1118005970.html and ask yourself if you're relying on self-selecting data a bit too much for what should be objective decisions.  Of course, being in a room with fellow fanboys and fangirls is a very good thing for very different reasons.