In this kick-off to the 2015 RWD Summit, I dived into latest research into the performance of the world's most popular ecommerce sites to answer the question: In the fight to offer shoppers the richest possible content on mobile devices, are retailers helping or hurting the user experience? This session looks at metrics such as load time, page size, page composition, and adoption of performance best practices. The goal is to obtain a real-world "shopper's eye view" of the performance of leading sites, and to track how this performance changes over time.