Just as Google won the search engine wars by helping people find what they are looking for, the e-commerce winners will be the companies that help people find what they want to buy (reliably and with confidence). Retail companies are blind to just what a shit-show their websites are (a lot of them even have ads in their online store). Any company that solves this problem for their sector will win it, and this is good…
It doesn't have total domination of ecommerce but frankly it'd run into anti-trust issues if it did. No company is going to do ecommerce bigger than amazon without getting broken up so yeah... amazon.