Just saw this thread. I do have over 10 courses on Udemy and as Bruce said, a number of students from all over the world. That’s the best part, people have found me that otherwise wouldn’t have known I existed.
Udemy is very strict about not promoting outside of their platform except on your bonus lecture, which is your last one. There you can link to your other sites and I have had students come and opt-in to my own list.
Udemy owns the list, but you can email your students from within it and promote your other Udemy courses.
I have had private clients come to me as a result of some of my Udemy courses as well, so it’s been a good platform for me. Plus I make a little bit of money from Udemy after they take their share.