There are lots of free classes on Udemy for marketing, economics, and other subjects. I've taken a few of them, some of which are more helpful than others. After taking the free program, I've gotten emails from the pros encouraging me to sign up for their paid program. I wonder if they're making any money that way. Give away a free class, then try to earn money by targeting the same people with paid advanced classes. Has anyone here tried marketing through free classes? I'd like to know if it works.