Girls are playing games. More than half of online gamers are girls, and gamers in general are getting older; this isn’t a hobby just for the kids. That means a lot of sexually active girls are talking to a lot of sexually active guys, and discovering they like each other. With guilds, raiding, and social gaming, girl gamers are also forming extensive social networks beyond the little circles of friends they knew in the pre-gaming dark ages. This also provides more opportunities for a hook-up. Those wild party animals at Forbes have the story.
Ever been to Goldshire on an RP Warcraft server? Cybering everywhere. I think cybering is part of this, since it allows girls to test-drive potential partners to discover what they’re into and what their personality might be like. Fantasy sex is a good start on real sex, it seems.