[v64]

I upvote things that I learned from or gave me a new perspective on. Reading the comment was a net positive use of my time. This can include comments I disagree with.

Similarly, I downvote things that I don't perceive as a positive use of time for me or for anyone else. Spam, grossly incorrect information, deliberately inflammatory comments meant to elicit a certain reaction, etc.

If a comment was a waste of time for me personally, but I can see how someone else might benefit from seeing it, I'll do nothing.