It used to be argued that long pages were a problem as users did not scroll. In 2010 Jacob Nielson found users spent 80% of their time looking at information above the page fold and although they do scroll, they allocate only 20% of their attention below the fold.
These days the perceived wisdom seems to be “It is no longer a problem, everyone scrolls automatically” to the extent that UXMyths quotes 11 pieces of research to support this point.
Now while I agree scrolling is no longer an issue for most people most of the time, there are some people for whom long pages are still an issue and some designs that can stop users dead on the page.
Firstly - People. What we see in testing is that some users don’t know the best ways to scroll. A small proportion of mouse users don’t use the scroll wheel, maybe they have never learnt? There is also a small proportion of touchpad users that don’t know about two finger swiping. I am guessing, but from watching our testing this might be as many as 10% of users. Most of these will painstaking try and locate the scroll bar arrow – a very small target – and click this to scroll the page. Most of these users also appear unaware they can grab the scroll bar or click between this and the arrow. It is painfully slow. On the currently de rigueur long pages this can take an age.
Now - Design. Some designs actively stop users scrolling. Things that made them think they are already at the bottom of the page. We recently tested a page for a client which had some content about a charity trek and then a big call to action button in the centre of the page to sign up. Even though there was further information below the fold most users did not get to this. The CTA made them feel they had seen it all.
So while most users will scroll most of the time you do still need to think about those that don’t as this is still a sizable minority and also be careful that you don’t accidentally stop the normal scrolling behaviour of most users.