What took so long for the German clone factory Rocket Internet to replicate Square? asks TechCrunch.
My answer: The Sawmer brothers probably waited for PayPal to enter the market in the hope of making yet another couple of hundred million dollars selling yet another business to eBay !! Their first business brought them several hundred millions when sold to eBay after some 9 months of existence (from memory). Since then they've made more than a wad of cash reselling European clones to US businesses -- they lately took several hundreds of millions from Groupon's VC cash.