With Facebook enduring a wave of public criticism for its cavalier approach to user privacy, it's becoming more apparent how important social media has become. I suspect it will be many years before the true scale and scope of the changes are appreciated, and even then much will never be fully understood. The era when humans interacted mainly by gathering in physical space, or maintained personal networks through one-to-one connections, has drawn to a close, and the next generation won't even really understand what that era was like. Social media has changed the meaning of human life itself.

It has also made a lot of money and investors have given companies like Facebook Inc., Snap Inc. and Twitter Inc. multibillion-dollar market valuations.

There's even an argument that the true economic value created by these companies is much greater than their profits — or, in Snap's case, their potential future profits — suggest. For the most part, the services are free to use. But given how much time people spend using them, it's probably true that they would be willing to pay a lot to keep being able to enjoy social media. In economics, this is known as consumer surplus — the amount of value that consumers get without having to pay for it.