A scraper would move on to the next page almost immediately, real humans take a while to get to the next page.
Then I click the back button, thinking that will do the trick, and click the next page link. Same error, because I never actually got a refreshed page when I went back.
So then I have to click back again, click refresh, then click the next page, all to go to the next page.
I understand that it may have been intentional, but it really hurts usability.
I sort of find it contradictory that hacker news itself feels a bit clunky, but maybe that's the point. Launch when you have something and eventually you'll know what is needed and what is just an annoyance.
I put it down to a (perhaps unintentional) * anti-procrastination device on HN's part.
Eg I'll load up a page worth of links and go read them. If by the time I finished reading and go back to HN to click on 'Next Page' and I get 'Unknown or expired link', this means that I've probably spent far too long reading already and should probably go and do some actual productive work.
* This doesn't always work as intended = /
I think the more important thing to worry about here is getting back to work, not the pages on a social news aggregator expiring for being open too long.
