Many years ago, clicking was the simple answer to this question. The general thought was that if you made your page too long, users would only view and read the top half and glance over or ignore the bottom half. Today, things have changed. Many users do scroll to the end of the page and have no problem doing so. Scrolling has become a second-nature and clicking a chore. As user behavior changes over time, designers need to take that into account in their designs.
Why Scrolling is the New Click, 01/10/12
I still today in 2014 get into heated discussions about designing web experiences where “above the fold” trumps scrolling. Can you imagine the outrage if Tumblr made us click to see the next post in the dashboard?