37signals posted a good series on this, including quantitative results. http://37signals.com/svn/posts/2977-behind-the-scenes-highrise-marketing-site-ab-testin

37signals posted a good series on this, including quantitative results. http://37signals.com/svn/posts/2977-behind-the-scenes-highrise-marketing-site-ab-testing-part-1 http://37signals.com/svn/posts/2977-behind-the-scenes-highri... http://37signals.com/svn/posts/2983-behind-the-scenes-ab-testing-part-2-how-we-test http://37signals.com/svn/posts/2983-behind-the-scenes-ab-tes... http://37signals.com/svn/posts/2991-behind-the-scenes-ab-testing-part-3-final http://37signals.com/svn/posts/2991-behind-the-scenes-ab-tes...