Why smaller-than-traditional consumer payments fail: "The function of prices is to let the shopper map personal resources (budget) to personal values (unique and not directly observable). This entails a significant mental cost." http://www.fon.hum.uva.nl/rob/Courses/InformationInSpeech/CDROM/Literature/LOTwinterschool2006/szabo.best.vwh.net/micropayments.html … https://unenumerated.blogspot.com/2015/10/minimizing-consumer-worry.html …
