On Facebook specifically:
With people creating, posting and interacting with more video, the composition of News Feed is reflecting this evolution of behaviour; 76% of people in the US who use Facebook say they tend to discover the videos they watch on Facebook.
"Expressing ideas through film is a core aspect of how creative people love to bring ideas to life. With the explosive growth of video on Facebook, it is exciting to see News Feed become the centre of discovery for this work. We are only just starting to unlock the potential of sight, sound and motion in a feed-driven world," says Mark D'Arcy, Chief Creative Officer of Facebook's Creative Shop
For marketers, mobility gives brands more opportunities to reach people in a visually vibrant way that transcends language barriers via the screen that is with people everywhere, all the time. For instance, kate spade new york recently launched "the waiting game" video, featuring Anna Kendrick on various platforms for the holiday including Facebook. In just under a month, the video had reached over 9.9 million people, over 1.8 million views and received over 49,000 likes, comments and shares (from 13/11/14 - 11/12/14).
For more information, go to insights.fb.