(Disclaimer: I first found out about the concept of natural monopoly in this article, so when I say I am not an expert, I mean I have no clue whatsoever.) Well

(Disclaimer: I first found out about the concept of natural monopoly in this article, so when I say I am not an expert, I mean I have no clue whatsoever.) Well, a natural monopoly doesn't mean that it is a monopoly, right? Just that it's most efficient as a monopoly. It's not impossible to build out an alternate network of power lines; it's just prohibitively difficult. Maybe it'd be more correct to say that it's Facebook's specific targeting mechanism of ad delivery that it has a monopoly on? For instance, I imagine a cellular network is a natural monopoly by the exact same reasoning you say that an electric utility is one. Except... neither Verizon nor AT&T nor whatever actually has such thorough market domination: in fact, their competition is partly on the very pervasiveness of that network.