Clear course and teachers, challenging quizzes. Some interesting and advanced concepts (for instance on retail, bids). You need some mathematical knowledge to pass (derivatives, algebra, statistics...)
If you already have a business / marketing education, half of the concepts and methods won't be new to you.
I would have like to have a bit more explanations for the final peer-graded exam. Also it can take some time (1-2 weeks) for 3 other students to grade your final assessment if not enough people follow the course at the moment.