I've had a couple of questions lately asking about the advantages of participating in certain aspects of Stack Exchange (e.g. earning badges, marking answers as Community Wiki), so I figured I'd ask: It's pretty clear why we need people to participate in moderation activities. However, what's the advantage to the individual of participating (besides the overall improvement in site quality, which obviously benefits everyone)?
A related question (and I can split this out into a separate question if people think I'm asking too many questions in one post or this makes the post too broad), but there's a lot of evidence that only a relatively small percent of people who have moderation privileges of various kinds (e.g. the ability to vote to close questions) actually use them. What determines who is likely to participate in moderation and who isn't? (That actually seems like an interesting game theory question, come to think of it).