Why the geek image is such a tread now?

I want to know why being a geek/nerd is such a trend now. I have been playing video games, reading comics and collecting figures for years and all of a sudden at my local comic book store i see preppy girls and guys coming in and looking very out of place. They are only coming in because it is seen as cool to be a geek now days. Ever since jay jays got t shirts in with ghostbusters symbols and teenage mutant ninja turtles on them its become a fad. I would like to know why the hell this is happening???