A fake fan is a fan of a band/artist who think's they know everything about a band, but in all honesty, only found out about them 10 minutes ago and is most likely following a fad and has only heard a hand full of songs and knows nothing about the band. Fake fans tend to get aggressive when you confront them about their fakeness. They are most related to Jonas Brothers and other popular teen stars.
"oh so who's your favourite member of the band?"
"Oh you know...the one with the long hair? he's cute"
"umm, fake fan much?"
"NO I'M FUCKING NOT. I'M A MUCH BETTER FAN THAN YOU, BITCH."
Some one who follows a big name sporting team only because that team does so well they have no connection or loyalty to that team nor do they reside or come from that teams local area
Fake fan:"I follow Manchester united"
Guy:"Oh who's your favorite player"?
Fake fan:"Uhm Ronaldo"
Guy :"Ronaldo hasn't played for United for 3 years now you idiot"
Fake fan:"Oh that other guy then Giggs"
Guy :(Thinks to himself) "fake fan" doesn't know nothing about the team he claims to support