I was answering a question at Linked In about motivating users and thought it would be good to keep my notes here as well.
- Points Points are a great motivator for users. You can use them any way you like. At the simplest level, points can be mapped to contributions or user actions and tabulated behind-the-scenes. Points can also be exposed to users, provoking competition to earn the most points. I you want points to be more than status symbols points can be redeemable for whatever you want (access to site features, virtual goods, real goods). This in turn creates a virtual economy for your community which can be very useful if you want to get some behavior to happen quickly like taking survey.
- Levels Create levels that recognize historic contributions. Make each level a status symbol for your users.
- Leaderboards You can use leaderboards to keep track of and publicize your best and most active community members. You can keep statistics on anything you want people to do: most invitations, most forum posts, most consecutive days logged in, etc.
- Collections Allow users to collect things that they can show off. Avatars of other users, sets of virtual goods, etc.
- Challenges Challenges give your users something to strive for. And after they’re earned, completed challenges can be displayed in the users virtual trophy case.
- Features Create tiered features that granting access to special content or functionality. This can also be a way to make points worth something in your virtual economy.
If you have other ideas add them as a comment.