Volunteer organizations motivate and compensate their members in a variety of ways. Most of the ones I'm acquainted with do so via immaterial rewards, which was your original question.

With respect to the new goalpost of "karma points" -- can you clarify what characterizes the set of "karma point" like reward structures? If the Catholic Church selling indulgences qualifies, I'm not sure why wikipedia granting wider edit privileges wouldn't, for example... those things are certainly different from one another, but then again both are different from karma points. I'm not sure what differences are significant, on your view.