Cute thread, although if people don't vote on stories, they might not vote on you poll
I must admit I only vote if I am going to give them a 4 (doing well, want to see more from the author) or a 5 (unique, brings something new, great writing style etc). I usually only leave a PC if the story seems to have a low vote, and shouldn't. Weird, I know.
How do you know if the story has a low vote? only the author can see the votes unless they're in the top 500