Skill points for helpful discussion posts
I am always impressed by the helpful and altruistic posts of native and advanced speakers to help clarify discussion posts. I think these folks deserve point(s) when their posts are recognized as helpful (ie, reviewed by the duo team or receive more than a certain threshold of vote-ups). These folks contribute to the value of the site tremendously, sometimes moreso than what is gained from some exercises.
I'd appreciate it more if duo would invest the time and resources to write clear, concise and error-free grammar intros to the lessons and thus reduce the "workload" for people who regularly answer questions in the forums.
Or auto-populate the main screen for each lesson with a user-contributed introductory summary that is voted up the highest. Those users who achieve this could receive distinction with more skill points.
I think they should do both. Some nuances or helpful tips are given by sharp students...