they will eventually start accepting bitcoin for sure. because they will be forced to do it pretty soon.
the decentralization is growing fast and all the centralized businesses like Amazon will die soon. we already have a very good project called "OpenBazaar" which does the same thing but in a decentralized manner and using cryptocurrencies.
when things like this gain more popularity and become easier to use they will take the market pretty fast out of the hands of businesses like Amazon.
This is alo my view on bitcoin, they should accept bitcoin very soon because there are many people seeing the advantages of blockchain and cryptocurrencies, man I hope they will accept it and let us profit hugely from this wonderfull technology, first step is to accept bitcoin as a payment method by Amazon, this will open many doors to smaller online stores and eventually over many places.
Eventually the world needs a fast payment method and I hope it will be bitcoin or one of the other good altcoins, what I certainly dont hope is that the corrupt governments dont make their own blockchain and currency.