I occasionally up-vote old comments. It works like this: I'll read a comment that I find really intriguing for some reason (love or hate, usually). Curious ab

I occasionally up-vote old comments. It works like this: I'll read a comment that I find really intriguing for some reason (love or hate, usually). Curious about the poster, I'll go to their "about" page and scan through their old comments, which I'll upvote using the same criteria as for new posts. Probably once a month or so, I end up giving 3-4 upvotes to one person this way.