I think the difference is between: 1) me doing a nice thing and them reciprocating later, possibly. Others may or may not see this display of niceness. 2) me doing a nice thing, getting karma points my friend and other sees, which I can possibly use to get perks of some kind.

Gamification is not a new word for an old idea. It's a new thing, at least in many contexts.

#1 seems a lot more human to me.