Chat is nice, but there are lots of ways to do that and I need something where I can make sure people are submitting feedback, otherwise I don't want to give them the discounted goods in exchange for the feedback.
I think I realized what will work.. some sort of e-learning software. I would basically just pass/fail each item tested on whether an "exam" was submitted, but I do have some quality requirements for feedback. Having used Moodle before a bit, I think you can give more or less points for multiple choice answers. I wouldn't care about the aggregate of these but maybe could use that too.
Best of luck with finding something suitable.