… Jakob Nielson, web usability consultant, author, and owner of useit.com, writes on his site about a recent research study by Harald Weinreich, Hartmut Obendorf, Eelco Herder, and Matthias Mayer …
… users will read about 20% of the text on the average page
Read Write Web – The Stats Are In: You’re Just Skimming This Article

visual heat map – source
The fewer words, the better. Compelling pictures and video, more important.
If something really jump out at you as important, follow the links for details.
