They found a strong hotspot over the scrollbar because users were looking at it as a cue for page length. It was also found that if you have less above the fold (one large content block as opposed to 2 smaller ones), it encouraged exploration below the fold. What they did find when people didn't scroll was that there was no visual cue to more content below the fold or there were strong horizontal lines acting as a barrier.
1. Less is more – don’t be tempted to cram everything above the fold. Good use of whitespace and imagery encourages exploration.
2. Stark, horizontal lines discourage scrolling - this doesn’t mean stop using horizontal full width elements. Have a small amount of content just visible, poking up above the fold to encourage scrolling.
3. Avoid the use of in-page scroll bars - the browser scrollbar is an indicator of the amount of content on the page. iFrames and other elements with scroll bars in the page can break this convention and may lead to content not being seen.
Our research shows the most effective place for content is above the fold, no surprises there. We are saying that people do scroll. Users scroll if there are cues to scroll and no design barriers to scrolling.