@paywithsteem What is it that you are trying to achieve with this feature?

To compete with giant like amazon you gonna have to pull merchants from their site and bring them onto yours.
Your strategy should be based on that ; how do I get amazon merchants to sell on my site?
The answer to this question is innovation. Amazon charges outreageous fees and their site is far from perfect. So there are improvement there.
And you should also consider the real competition which is sites like openbazaar which charges no fee at all. People can already pay with steem on openbazaar, the site is still not very popular because it lacks a browser version but the future is going to be free and decentralized trades, keep this in mind :)