Well, because they conduct Facebook, Twitter and Instagram and maybe even more accounts and need to tell 5-25 stories every day, and they can't all be just about their products and how great they are. In this regard, everyone mentions Red Bull, but there are more and more companies that create their own in-house content studios, and they are right in doing so. In a survey by a firm called "levels beyond", 61% said that they would watch a brand's video if it were shared by a friend. 67% say they like how-to videos and tutorials (which maybe also is a reason why YouTube is the second biggest search engine after Google). At the same time, in this same study, 75% of marketers researched said that they rarely or never produce video.