There’s a lot of debate over the importance of “above the fold” (ie within the viewable area of the screen without scrolling) and whether online readers are happy to scroll rather than click/flip pages.
My philosophy has always been that your most clickable content should be above the fold, but that as the internet evolves and people’s browsing situations become more and more comfortable (think laptop/iPad on couch rather than clunky desktop at uncomfortable desk), they’ll be more likely to read on-screen for longer. That said, I think attention spans will always be shorter online than in print, for the simple reason that there are more distractions.
A recent issue (“Scrolling and Attention”) of usability researcher Jakob Nielsen’s Alertbox newsletter dealt with this issue. His conclusion was that you should prioritize design so that the most important information is above the fold, but that users will happily scroll if the information architecture sends them down the right path. He also suggests making sure there is clickable content at the end of the page as this is where users will go next if they make it that far (e.g., if they read an entire article, they’re not likely to scroll back to the top to click on a related article – better to put something relevant at the end for them to click on).
His article also provides a few screenshots of eye tracking on websites that are worth checking out. It’s interesting to see where readers’ eyes go and how they scan down the page.