With their parents invading Snapchat, American teens have found a new social network to call home. Musical.ly is a video app where users share 15-second clips of themselves lip-synching and dancing to pop songs. It already has 90 million users, including half of all US teens.

Vertical video was once the much-ridiculed byproduct of smartphone clips filmed the ‘wrong way'. But the popularity of Snapchat and other portrait-mode video apps is prompting content platforms, advertisers and even filmmakers to take it as seriously as users. Is vertical the future of video?

With a valuation of more than $15 billion, Snapchat has already proven that vertical videos work. Facebook is now looking to tap into that success, with the social network announcing the launch of vertical video advertising – and people seem to love the new format.

One in three teens claim they could make money by creating YouTube videos. The success of social media stars like Bethany Mota shows that celebrity endorsements aren't influential as they used to be. Today's teens want inspiration from cool kids who could easily be their mates.