" One way to appreciate the brilliance of this acquisition is to look at Instagram’s “Power Index,” the number of people a platform reaches times their level of engagement. This social index reveals Instagram as the world’s most powerful platform, as it has 400 million users, a third of Facebook’s, but garners fifteen times the level of engagement. L2 Analysis of Unmetric Data. "

― Scott Galloway , The Four: The Hidden DNA of Amazon, Apple, Facebook, and Google