Den 10 feb 2015 11:34 skrev "MⒶrtin HⒶboⓋštiak" <martin.habovstiak@gmail.com>:
>
> Why would anyone want to do anything about payment before choosing
> what he wants to buy and for what price? I've never used Amazon but
> isn't filling a form with shipping information enough?

That's not what this is about.

BIP70 isn't just payment, it is about communication the terms of the sale.

Let's say you're visiting an international webshop. But they don't ship to your country. Wouldn't you want to know that before your start filling the cart? With this, your wallet / browser extension could tell you right away that you can't shop there. No time wasted!

That's just one requirement of many where you would benefit from being told right away if it is acceptable for both parties or not.