I have a theory on this: The url of the 'more' link is some kind of hash of the next page of links at the time of page load, this is because HN Moves pretty qu

I have a theory on this: The url of the 'more' link is some kind of hash of the next page of links at the time of page load, this is because HN Moves pretty quick, so using the live data you're likely to miss links between page 1 and 2. (Which is what happens on 4chan) Obviously these links have to expire fairly quick as they're pretty unique, and storing them for much time would use a huge amount of memory. With this in mind, the life span of these links is probably directly related to the current load of HN. Amirite?