You never touch pvt keys... Amazon is accepting 0 confirmation payments assuming the cc company takes care of fraud or double spend in ourcase. We can simply say accepted too and them give option to wait for comfirmation or emAil me if something went wrong(your bank accoun had nsf error) eitherway amazon 1 click is just illusion masking the same problem which we can mask the same way...
Yeah exactly. The blockmarket website the vendor is running could add a login and "trust" a repeat customer to not need to confirm, much like amazon 1 click, if they wanted to. It is not the blockchain's responsibility to do that.