"Generation Like"

Generation X or people born around the are 2000 have been reffered to as "Generation Like" by Frontline. First, I did not know that my generation was being labeled as "Generation Like". Considering most of our lives have been involved in Social Media it makes sense. Second, I did not realize how many people Tweet about their favorite band, show, movie, ect. Along that same line, I did not know that by Tweeting about a particular media such as a movie you are making them money through "free" marketing. I would like to know more about how much money is being made through "free" marketing.