One of the great things about open learning environments like MOOCs is that effort gets recognized in ways that go beyond grades. Even in a course with tens of thousands of students, there are individuals who–through their extra effort in answering questions and fostering discussion–enrich the learning experience for everyone participating.
Now, 14.73x The Challenges of World Poverty is recognizing these contributions through the creation of a Community TA role. From their letter to the 17.43x community:

…we have selected a few of the most active, most helpful and most resourceful community members on the forums to become TAs for the course. These TAs will be in charge of moderating the forums along with our staff, and will have both the responsibilities and privileges that go along with being a TA….
The goal of selecting Community TAs is to enhance the 14.73x community’s learning experience. We have tens of thousands of students registered for the course, and although our staff is hard at work to answer each and every question, we want to enable all stellar students to have their questions answered so they can learn as much as possible throughout the course.

This speaks to the importance of community in these courses where so often the discussion is about the content.