This will depend completely on your current level of technical skill, whether or not you've already got a product/service ready to launch, how much you know about online marketing and how much time you put into it. I managed to build and launch my first course in 3 months without any help, so I'm going to suggest a minimum of around 3-6 months for most people to make their first sale assuming implementation time on a module every 1-2 weeks. If you're just watching the videos, you'll complete the course in around 7-8 hours.