I am sorry. I hate it when i have to do this, because i know that it's really silly! But the only reason why i wouldn't 粉丝 anyone back, would be if they had joined the twilight saga club. I can see it on their 个人资料 and i immediately go all prejudice against them.
I shouldn't, i know, but it's against my morals to 粉丝 someone who loves the Twilight saga. If you're only a 粉丝 of Twilight, sometimes i forgive you... if you've done something to earn my respect.

Which would lead me onto my 下一个 reason...
If 你 have done nothing to earn my friendship, and not joined any of my favourite/major clubs, then i don't feel obliged to 粉丝 you.
However, if i can see that you're a 粉丝 of 'Random' 或者 'Harry Potter' 或者 'HP v T' etc, then the probability is that i will 粉丝 你 back.

On the other hand, if 你 are looking at this thinking that 你 haven't done any of these things, then feel free to 粉丝 me... i'll gladly return the favour! :)
xxx