Someone who becomes friends with a person, adds them on Facebook, then decides that the friendship can be maintained entirely on Facebook. They do not bother to organize to meet up with this person, sometimes they might not even acknowledge them when they walk past them in the street. Furthermore, they appear on Facebook to be great friends because they write on each others walls.
Person A:"I have 629 Facebook friends!"
Person B: "Wow, you must be getting constantly stopped in the street and chatted to."
Person A: "Meh, not really."
Person B: "You Faceslacker!"
Person C: "You're a cyberwhore. Haha, POKE!"