I've had great experience as a user of Udemy and write my own courses but offer those privately for my clients.
It's always better to build a course that answers a specific need. Think about the avatar for your business. You can't meet everyone's needs. Build a course with no more than 8 segments or modules with 4 - 8 learning segments within each module. You will allow the user to achieve rapid and measurable results by completing each section and ending each module with an assessment (quiz) that further validates learning the skill. Udemy is easy to use so you will have a broad audience looking for specific needs.