Betfair is rebuilding their website to improve performance and address customer complaints of slowness. Their plan is to deliver incremental improvements, build functionality in slices, and expand offerings over time from April 2011 to January 2012. They are optimizing performance through techniques like reducing HTTP requests and deferring non-essential content. Their goals are to achieve 3 second page loads for 95% of customers under peak loads using common browsers on typical bandwidths. Initial customer feedback indicates pages are loading faster with improved sessions and engagement.