89% of Chatroulette users are male

"For more than two weeks earlier this spring, RJMetrics compiled detailed data on 2,883 Chatroulette sessions that tied users to things like geography, gender and appearance. The data showed 89 percent of users were male and 11 percent were female. (Users are more likely to come across a Webcam featuring no one than to find a female alone.) Some 8 percent of spins showed multiple people; one in three females used Chatroulette as part of a group versus one in 12 for males. As for the perv factor, one in eight spins came up with something R-rated."
Source: RJMetrics, reported in Adweek, 12th April 2010