Someone who even though they have friends on Facebook, never interacts with them. They never have wall posts or are in anybody's boxes. They seem unpopular on social networking sites, even though they may have friends in real life.
Oh, I know her. She's such a facebook loser.
i. Acts incredibly sad on social networking sites, like Twitter, MySpace and especially Facebook.com
ii. Acts nothing like their online alter-ego in real life
iii. Spends majority of the day on social networking sites attempting to "pick up chicks"
Brian: Hey dude, did you see this hot chick I found on facebook.com?
Steve: You're such a facebook loser!
A person that acts incredibly sad on social networking sites, like Twitter, MySpace and especially Facebook.com, constantly posting pointless statuses that only they like asking people to hangout with them, what people think of them and if someone likes their status they will tell them something. Acting like they have an extremely popular social life often talking about going to the Gym, Drawing, Working or other irrelevant activities that don't require other individuals.