No, Facebook isn't going to die tomorrow. It'll still be around 5 years from now. After all, even AOL is still clinging to life.

But their valuation depends on extrapolating today's growth and cash flow into the future.

So even a slight slowdown in their growth rate or small reduction in margins can have a magnified effect on the company's valuation.

Since expectations of higher future valuation drives high compensation for strong performers, any hint of this unraveling will result in brain drain.

It's almost certainly already begun.

Yes, my mom will still be on Facebook in 5 years. But I won't be there, my kids won't be there, and my friends won't be there.

Since the network effect works in reverse, the users who remain will spend fewer minutes per day on Facebook and Instagram than they do today.

And ARPU is dismal for the fossils who think Facebook is the internet.