Look at the amount of people who have bitcoins, could save 20% by spending bitcoins on Amazon and yet do not spend their bitcoins on Amazon.
What in the world would make you think that Amazon accepting bitcoins at the same price would make the price go up?
Even if Amazon started accepting bitcoins, they would immediately exchange them to fiat (which would drive the price down).
At least with purse.io people are not automatically converting them to fiat.
because amazon have one thing better than purse.io and i believe it's the main reaosn why only few are using purse.io
it's the return policy and the faster delivery, with purse.io i know you can return but it is not straightforward like with amazon, i'm sure some trouble may arise