On the original point: I think at equilibrium services like Facebook maximize total welfare, then take their cut in a socially efficient way (e.g. as payment). I think the only question is how long it takes to get there.
Why? There are plenty of theoretical models in economics where at equilibrium total welfare does not get maximized. See this post and the standard monopoly model for some examples. The general impression I get from studying economics is that the conditions under which total welfare does get maximized tend to be quite specific and not easy to obtain in practice. Do you agree? In other words, do you generally expect markets to have socially efficient equilibria and expect Facebook to be an instance of that absent a reason to think otherwise, or do you think there’s something special about Facebook’s situation?
Why? There are plenty of theoretical models in economics where at equilibrium total welfare does not get maximized. See this post and the standard monopoly model for some examples. The general impression I get from studying economics is that the conditions under which total welfare does get maximized tend to be quite specific and not easy to obtain in practice. Do you agree? In other words, do you generally expect markets to have socially efficient equilibria and expect Facebook to be an instance of that absent a reason to think otherwise, or do you think there’s something special about Facebook’s situation?