i have so far 751 up-votes and 17 down votes. i give someone an upvote is their questions makes me think of something i had not thought of before, if i find myself nodding along while i read it or if i wish i had though to ask it myself. if its well thought out,researched, hyperlinked, and also succinct then ill upvote it. if it makes me laugh out loud (and that was the intention of it), then ill upvote it.
if its a question ive seen ten thousand times (is dairy paleo?) i dont even bother to open the thread, let alone vote for it.
i down vote when i think a question should be closed for being very off topic, shameless self promotion, or just plain nasty. i downvote comments that i think are unnecessarily rude or smug. if someone made no effort to read the FAQ or hang around for a while to see how the joint works before posting, i might downvote.
i do NOT downvote someone just because i disagree with them. i do NOT downvote people if i just dont like them.
ive been involved in a few online forums in my life, and this has been by far the most intelligent, welcoming, and helpful. i value the people here in their diversity of knowledge and experience. in general, i think that everyone here has just the best of intentions, and that this community does an excellent job of policing itself.