LiveAgent: Over $250K monthly recurring revenue with a spin-off project 8 years ago
The company offers training and various courses to the apprentices. The students are generally studying things not related to businesses or digital marketing. They are only interested in these topics and want to learn. So while they watch the courses and read articles, they practice working inside real businesses.
I don't think it's a bad idea, as in many times the real knowledge comes from practicing and using all the techniques you have learnt. But agree that working for free sucks.