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.
MIRI is gathering a bunch of Eliezer’s writings into a nicely-edited ebook, currently titled The Hard Part is Actually Changing Your Mind. This book will ultimately be released in various digital formats (Kindle MOBI, EPUB, and PDF). Much of the initial work for this project is complete. What we need now are volunteers to review the book's chapters to:
This project has been added to Youtopia, MIRI’s volunteer system. (Click “Register as a Volunteer” here to sign up. Already signed up? Go here.)
LW Karma Bonus
For this special project, every point earned in Youtopia will also earn you 3 karma on LW!
Points are awarded based on the amount of time spent proofreading the book. For example, an hour of work logged in Youtopia earns you 10 points, which will also get you 30 LW karma. Karma is awarded by admins in a publicly-accountable way: all manual karma additions are listed here.
Questions about this project can be directed to alexv@intelligence.org or in the comments.