[corank]

My hypothesis is that the PDF format bears much blame here. The results might be very different if the material is in a reflowable format like an epub or a web page. If you think about it, the notion of a page exists only because of the physical limitations of the paper medium, and PDF is page-centric only because it was designed to represent printable materials. There's no reason to stick to pages anymore if the material is to be consumed on a screen, and PDF is therefore also the wrong choice for this.