I was recently designing a presentation in which I wanted to give examples of humans responding to non-material incentives, specifically responding by doing an action faster, earlier, or with more care. I know of these sorts of gamification strategies used in the sustainability world, including "the 'Prius effect, when hybrid drivers use feedback on their car dashboards to challenge themselves to drive more efficiently, to utility consumers in Sacramento competing with their neighbors to see who can save the most energy" described on the GreenBiz.com site.
What I'm looking for, though, are more every day examples that a general audience could relate to, especially regarding mundane tasks. I keep thinking of expiration dates on milk (which I, for one, respond to by seeing how much milk I can chug the day before it expires), or carpet that shows vacuum lines very clearly (which gives me an incentive to actually vacuum the entire room), but I'm worried these are artifacts of a particular personality and not readily experienced by most people.
Ideal examples would be something like "You take more care to brush your teeth when . . ." or "You'll might get a gold star so you take more care to . . ." or "People will try and do the task more quickly just for fun when . . ."
Any suggestions?