Too many sites I go to take a long time to render - often times over 30 seconds. The page displays but freezes so that the user is unable to scroll down and often the site temporarily freezes the browser so that one is unable to go elsewhere. (I find this issue to be more prevalent with IE than Firefox. It also applies only to the tabs and windows associated with that particular session.)
I've looked at the coding of these pages. Most of them are professionally done. The coding is fine and the graphics of reasonable size. So why do the pages take so long to render?
Another big offender is the practice of preloading videos and podcasts. Developers cannot make the assumption that users will want to view these items. In delaying the page rendering in order to pre-load the videos they are alienating viewers. It may be a tough decision but pre-loading may not be an option.
See an earlier article: @Font-Face and Page Rendering