Learn Microsoft SQL
Expired and out-of-date content can prove to be a goldmine.
This is a course for a now-retired IT exam but it teaches databases from beginner to intermediate level. Instead of deleting it I put it up on Udemy and never looked at it again. It’s had over 900 sign-ups so far.
Udemy is a great idea if you don’t want to host your own content and worry about payments and development costs. Udemy takes a share of the profits and you will still need to provide student support.
I teach how to make exams to sell on Udemy on the – Sell Practice Exams on Udemy course. It’s just a side project for me, but it brings in around $1,000 per month.