Interesting piece on checkout evolution: "checkout is the lynchpin of e-commerce. It’s how customers buy and retailers get paid. Yet despite years of evolution, only a few changes have significantly impacted checkout conversion online."
While some e-commerce checkout forms vary from a standard sequence, most don’t. In fact, even the order of questions has become quite standard: personal information, shipping information, billing information, and a final verification step. This sequence actually builds on itself as shipping addresses determine final costs (shipping plus tax) and are often re-used for billing addresses. Details like this have been analyzed and optimized over the years to make sure that checkout throughput is everything it could be.
"Yet despite many years of optimization, online shopping cart abandonment rates reached 75% in the first six months of 2011. No wonder many companies are looking beyond standard form designs to improve their e-commerce conversions." See source: Shopping Cart Abandonment Rate Tops 75%
Then follows a number of suggestions for improvement....such as saved accounts, free shipping, real-time feedback, better layout, psychological motivators and paying more attention to mobile.