Youtube (adsense) collects your money and asks for payment info only when its time to pay. But in Amazon we first need to provide payment info this discourages paid apps.
On youtube people are more likely to start business and put their most effort easily. But in amazon it discourages business. In youtube people often try to test their market potential but here you have to first decide. Its not handy to create a bank account in every country.
(Yes I know they both are of different platforms but here I am comparing their transaction model)