I reward myself when I do something good for myself. This could be a drink, an ice-cream, a dinner, a mobile phone... And if I do something good for others, I want to be rewarded. Not must be a material thing, but a nice word.
I think this should be done at workplace especially. By doing so, managers would increase the motivation of their asistans.
I think in the workplace reward is better than socially these days. Not everywhere of course. Too many socially are so disconnected that they don't care about others - but in the workplace, they look to improve productivity and know reward matters - monetary being low on the list as a motivator.