In December 2013, Facebook had started "Auto Play Videos" for all mobile users. According to this feature, when a user scrolls down the News Feed, the videos uploaded by advertisers are automatically played.
This feature has widened its doors to most of the advertisers which will be 15 seconds long display on the screen. Due to this many of the visitors' attention will be grabbed resulting in the business bloom of the video advertisers.
As per the sources, the ads are going at rates of $1 million to $2.5 million per day. Users who are the end visitors will see the video ads from late April or early May.