One bit of advice I heard repeatedly in the corporate world and in manage books was to keep it brief. When presenting to upper management the advice was always "Be Brief, Be Bright, Be Gone." Another commone bit of advice was to develop an "Elevator Speech." We were advised to have a quick 30 second summary of whatever project we were working on. By having this quick speech ready, if we happened to get on the elevator with the President or CEO, we could deliver our "Elevator Speech."
How is this relevant to web design. The average visitor will only stay on a web page for 58 seconds. If your pages go on and on ( as mine often do ), chances are you will lose the reader's interest. Go ahead and write your masterpiece. But then give it to someone else to chop it down ( as I always do), and reduce it to three or four concise paragraphs.