Students who downloaded a podcast lecture achieved substantially higher exam results than those who attended the lecture in person.
I remember going to class at university and wondering whether I should record the lectures. I never did this because it was easier and more efficient to take good notes during the lecture and then meet with classmates to compare my notes. What if I had the option to attend the lecture or download a podcast of the lecture (and not attend the lecture)? I might have opted to download the podcast and never go to class (unless there was a useful class discussion).