If one clicks next to go beyond the first page repeatedly, there is effectively a timeout how much time can be spend until the link expires and one has to start from the beginning.

I think this makes it more tempting to upvote something just after looking at the headline instead of after reading it, because one has to remember so much or use so many tabs or bear with going back to the front page and clicking next again.

I have no idea about everone's behaviour, but maybe expired links in the end also affect something like users voting up fluff posts?