The thrill of unboxing predates the social media trend for watching videos of it. Opening up a box containing new, uniform-compliant school shoes can be as exciting for a child as unwrapping a birthday present. Despite their future being clear—several seasons’ worth of scuffing before they start to pinch—for a moment those shoes are spick-and-span, perfectly arranged and full of promise. 

Recently, this thrill has taken an odd twist: There are currently more than 100,000,000 videos on YouTube featuring people opening products and packages. The first video described as an “unboxing” (item: a Nokia cell phone) was uploaded in 2006. Since then, these videos have come to serve as reviews, relaxation aids and a glimpse of a life less budget-strapped—sometimes all at once. Conten...