Creating an online course is a great way generating revenue and expanding your profile at the same time. However in order for it to be successful you will need to establish whether there is any demand for what you offering. The best way to do that is to poll your audience and find out what they want from you.
If you don’t have much of an audience, you need to start building one. The quickest way to do this is to create some sort of free gift or giveaway that people can download from your website in exchange for their email - The technical term for this is lead magnet.
As you gather emails, continue to send out valuable content that your subscribers will appreciate. When your audience is of a suitable size you can begin to ask them what do they want from you and how much would they pay for it. This will give you an indication of not only what to create a course on, what the level of demand is and what people are prepared to pay for it.
Although this is a lot of hard work in the beginning, it is a far more costly process taking time off work to build and film a course that nobody wants to pay for.