The thing is Hairy, there are too many thumbs. When a post gets 30+ TUs you don't really note who gave them. A joke I posted got 200, now that's crazy, people were voting for freedom of speech, not the funny.
I do like the idea generally though, especially if someone gives a day old post a tick, you go back and see what has been posted since you were last there.
BTW I am pretty mean with them, I hope nobody notices.