Although Facebook started as a place for college students and younger, it has grown up a lot in the last few years and is now a network for everybody. In 2009 the fastest growing demographic on facebook was aged 55 and over, growing by 922%. The largest overall demographic was ages 35-54 which makes up 29% of all users.
Keep this is mind and write for all audiences not just Teenagers. Many companies make the mistake of assuming that the only people on Facebook are college age and younger. Branding toward only this younger demographic could easily turn away a large amount of users