I was reading an article the other day (which I think was in the Economist although I can't find it on-line) about gambling and how you are more likely to win by backing the favourites than the rank outsiders (which is what most people do) - although what the statistics showed was that your net losses were less which isn't quite the same as winning.
In the article they puzzled over why people persist in betting on outside chances, but seemed to miss the obvious answer that people would prefer to risk a small amount on the chance of a big win (e.g. 100/1 odds) than to risk a bigger amount on the better odds of a much smaller win (e.g. 2/1 on).
I thought that this item on the BBC News about people being encouraged to recycle by the offer of prizes was the same sort of thing; however unlikely the win, it provides motivation for the small effort involved which the marginal benefits of an individual act of recycling do not.
There are always mundane tasks to be done in a job, e.g. filling in timesheets so client's can be billed, and the usual way of handling these things is to send out entreaties urging staff to do the right thing or reprimands telling them off for not doing it. Would it not be more motivational for employers to offer entry into a prize draw for those staff who make the effort?