I think Nick had good point: mental overhead of decisions (how much am I willing to pay for something) is real and people want to avoid that. I certainly do.

However, the conclusion that this will make micropayments fail was likely wrong, since it looks like we can simplify the mental overhead and still pay as you go with micropayments. For instance, by setting default tip/zap/boost amount and then just listening to podcast, or reading content and taping like button. We can agree once on electricity rate but still pay as we go, each second only the amounts we use.