One of the latest trends is to use game dynamics to make your website or app more engaging. Here is a long list of game dynamics that you might consider using. The list is apparently from SCVNGR as was leaked by TechCrunch where examples and more details are provided.
1. Achievement2. Appointment Dynamic
3. Avoidance
4. Behavioral Contrast
5. Behavioral Momentum
6. Blissful Productivity
7. Cascading Information Theory
8. Chain Schedules
9. Communal Discovery
10. Companion Gaming
11. Contingency
12. Countdown
13. Cross Situational Leader-boards
14. Disincentives
15. Endless Games
16. Envy
17. Epic Meaning
18. Extinction
19. Fixed Interval Reward Schedules
20. Fixed Ratio Reward Schedule
21. Free Lunch
22. Fun Once, Fun Always
23. Interval Reward Schedules
24. Lottery
25. Loyalty
26. Meta Game
27. Micro Leader-boards
28. Modifiers
29. Moral Hazard of Game Play
30. Ownership
31. Pride
32. Privacy
33. Progression Dynamic
34. Ratio Reward Schedules
35. Real-time v. Delayed Mechanics
36. Reinforcer
37. Response
38. Reward Schedules
39. Rolling Physical Goods
40. Shell Game
41. Social Fabric of Games
42. Status
43. Urgent Optimism
44. Variable Interval Reward Schedules
45. Variable Ratio Reward Schedule
46. Viral Game Mechanics
47. Virtual Items