stackoverflow has a few interesting incentives: - activity is renamed to 'rep' which implies that your activity ranking reflects on you personally, even though

stackoverflow has a few interesting incentives: - activity is renamed to 'rep' which implies that your activity ranking reflects on you personally, even though everyone knows its really a measure of how long you've been active and whether you answer broad beginner questions that get a lot of google hits - it makes sure you know when you are downvoted - though the numeric penalty of a downvote is negligible, but since it is a personal criticism of your reputation, you have ego incentive to improve your contribution