Income

Enough to quit my day-job.

I listened to student feedback, QA, reviews, had subtitles fixed, made better promos, better course descriptions.

In my Facebook I asked for people to look at my courses to make them better or find mistakes or places they could be clearer.
I gave 30 coupons away, 20 never did anything (other than get a free course), 6-7 sent me a few sentences of suggestions, but the last 3-4 sent me pages and pages of suggestions and clarifications. Some I implemented, some I did not (if they were not relevant, or were the way they were because that is how that certification would ask it or phrase it).

The 3-4 that I got all the feedback from got free coupons to all my courses as a reward.