>Before Facebook, if I lost someone's contact information, and drifted outside of their social circle for a long enough time, chances were I would never ever see or speak to that person again.

And chances are you are never going to speak to that person again even if you are friends on facebook.

The only thing that facebook invented is how to increase user engagement by finding loopholes in our psychology and get us addicted to their products.

Facebook did not invent anything other than making this world more chaotic.