As an instructional designer, I don't know why so many people are surprised with this. If you spend more time interacting with your students, instead of teaching at them, they are bound to achieve more in the course.
I cannot find the article at the moment, but earlier this week I was reading about an instructor who, instead of lecturing, used edX's circuits MOOC in his course. He then goes on to state that instead of spending his time lecturing, he significantly increased the amount of time he spend corresponding with the students--in other words, he flipped the classroom. The result was a significant improvement in exam scores
As stated here before, this goes back to Socrates. Instead of lecturing at your students, telling them what to think, interact with them, question them, get to know them, etc.
Good teaching transcends modality and fad.