SANTA CLARA, Calif.--(BUSINESS WIRE)--XpressBuy, a Commerce platform for marketers that powers Buy Buttons and enables consumers to engage and purchase from any context, today announced integration with four of the world’s largest e-commerce platforms, including Demandware, IBM WebSphere Commerce, Shopify and Magento. Through these relationships, XpressBuy is now available to an industry-leading 30 percent of Top 500 retailers. XpressBuy setup for retailers is achieved through a simple layer of