By Facebook invitation, I mean one where it is clear that the person has handpicked certain people to come to a party or something like that, not something where the person has invited their whole friends list to gain publicity for an event.
Do you think it is a little rude to decline a Facebook invitation without writing a message, such as "Sorry I can't come, have a good time!" or "Thanks, but I have something else that day"
To me, writing a short message compared to just clicking no and saying nothing is comparable to:
A: Hey, want to come over tomorrow?
B: Sorry, I can't.
vs
A: Hey, want to come over tomorrow?
B: No. *blink*
What do you think?