Processing a credit card costs $0.02 per card, plus interchange of up to 3%. Debit processing is $0.22 cents plus 0.05%. Both of these are the baseline cost, your merchant processor often won't be able to even get these rates for their own wholesale rates.
Now try and build a micropayments ecosystem ontop of this infrastructure that is very expensive to interact with (in the context of $0.01 charges). Amazon can do it for AWS as they aggregate many small charges into one bill, resulting in the service cost not being dwarfed by the payment processing cost.
Now try and build a micropayments ecosystem ontop of this infrastructure that is very expensive to interact with (in the context of $0.01 charges). Amazon can do it for AWS as they aggregate many small charges into one bill, resulting in the service cost not being dwarfed by the payment processing cost.