That brings back memories of my little brother shaking his "Pokemon Pickachu" nonstop for two weeks to earn volts 
It's a really clever idea, though! They reward you for taking the handheld with you which is awesome! Well I guess playing it more often also increases software sales hehe 
@BenVTrigger: It may lack an achievement system but I think it shows you how much time you put into each game. And Streetpass is also some sort of way to "show off" I guess. It surely is different from other systems, though.







