If you send me a friend request and don't add a note telling me who the h*ll you are, you will be ignored.
If I look at your page trying to identify you [just in case you didn't send me the note referenced above] and you have over 1000 friends, you will be ignored [Really, how can one possibly keep up with that many people on Facebook].
If I know you and already know we have *nothing* in common, I will probably ignore you. If I don't want to offend you I will send you a note to very nicely explain why I'm not going to accept your request. If I don't even like you, you'll get nothing.
This is how I roll...