The sense of community and lively discussions it encourages are things that Blackboard or Moodle might not be able to generate. The whole point of utilizing the internet for education is to bring the classroom to the students. The reality is that academic learning tools remain to be classrooms that students have to make an effort to enter. Using Facebook and other types of social media on the other hand brings courses to where the students are truly are... logged onto Facebook. As educators, we have to cast our nets where the fish already are. When we do this, it's like shooting fish in a barrel.
As a student myself, I believe that the best way to keep me motivated and engaged in my studies is to have the material delivered in a medium that I am already plugged into. For instance, I go on YouTube all the time for any instructional needs I may have like how to fix a car or how to tie a neck tie. I am a very audio-visual learner and I really appreciate the fact that my grad school instructors use videos as a supplement to our classes.
In my experience as a coach and educator, I have always had to find ways to use social media as a way to keep students in my classroom so to speak. Extending the reach of our class to their social comfort zones, albeit virtual, has really helped my players and students stay up to date with announcements and lessons. They even respond to me on an almost instantaneous basis just because they are always on social media. In tech terms, that's a great exploit.