I don't understand Clay Shirky's argument. He repeats several times that micropayments have not come about and treats this as evidence both that they cannot wor

I don't understand Clay Shirky's argument. He repeats several times that micropayments have not come about and treats this as evidence both that they cannot work and that users hate them. How can he be sure, since micropayments don't exist, that they would fail if they did exist? What about an App Store that charged 50¢ for an app? What about a chance to add-on a 15¢ donation to a charity after buying a stream of a $1.15 TV show? These don't sound like such taxing choices to me ("low mental transaction costs" in Shirky's phrasing). Shirky refers to "history" several times but he's a bit vague about it. I'm not sure whence he draws his conclusion about user opinion. Maybe he is thinking of some examples that I'm not. In my view "history has taught us" that once a system becomes familiar to users, they accept it and work within that system. So it then reduces to a chicken&egg problem.