Your name will be listed in the end credits of the film. You will also be given exclusive access to to a monthly production diary detailing the progress of the film and telling interesting stories that may not make it into the film.
All of the above, AND...the privilege of being informed about interviews before they happen. For each major interview, you may email the director one question which will be translated into Chinese and asked to the subject during the interview. The subject's answer may not make it into the final film, but you will receive access to the uncut footage. (note, in some cases where interview subjects are on a rushed timetable, this may not be possible)
ALL of the above, AND...You get everything listed above, but instead of being listed under "thanks", you will receive an executive "producer" credit for the film. Should you ever visit Beijing, you'll get a free dinner out with the film's director, and a chance to meet some of the film's subjects (pending their consent, of course).
Wow. You get everything listed above, plus periodic personalized updates from the director on the progress of the film, and the right to schedule skype conversations with the director to make suggestions, comment on footage you've seen, or offer constructive criticism.