Facebook’s News Feed is used by upwards of 1 billion people every month, representing 360-video’s best chance so far to reach a large audience and break through to the mainstream. Perhaps that’s why, as I meet with members of the Facebook team, they speak of 360-degree video with outsized enthusiasm. "There are certain things that, when you hold them in your hands for the first time, they attract a crowd," says Chris Cox, Facebook’s chief product officer. "People come to tell you they just saw it, and you have to see it. There aren’t that many of those. This is one of them."