The race for leadership in easy e-commerce in Europe is on. Stripe, the U.S. startup that has developed a simple payments API for developers to use in apps and on the web, is preparing to make its first steps into European waters with a beta launch. And the news comes as Rocket Internet-backed rival/clone Paymill, which also offers developers an API for simple payments (at comparable pricing), has announced a further round of funding, $5 million, from new investor Blumberg Capital, as it redoubles its effort in the region.