What do 'Gossip Girl' and Hannah Montana have in common?

Regardless of your age or gender, Gossip Girl has something that appeals to youbetween the show's dramatic characters, the sometimes convoluted plot, the unique music and the gorgeous fashions, there's a little something for everyone. But there's no arguing that GG has succeeded in building a die-hard fan base of young "tween" girls whose passion for TiVo-ing the show or downloading it on iTunes led to it being the first new fall series to be picked up for a full season. These girls are a movement in and of themselves, and they've got a surprisingly strong grip on the economy. Leighton Meester stars as Blair Waldorf in Gossip Girl. Blake Lively stars as Serena in Gossip Girl.