HN is a way to find interesting stuff. This includes older material. If people don't find it interesting, they won't vote it up.

You are of course 100% correct (although it seems to me that most stuff on HN is "new" stuff). My gripe is that I use the RSS feed so I see EVERYTHING that gets posted to HN, and this is one of those posts where I feel like the target audience is quite small, and those who need it will have no issue finding it themselves. But I guess I'm just biased because I have actually used this book before, and therefore don't find it interesting at all when it is brought to my attention at a time where I have no further use for it.

I don't have the links handy, but there are RSS feeds that only serve up HN items that hit certain point levels, such as 20, 50, or 100 points. I like them because there is often a lot of noise getting submitted to HN and often only want to see what has managed to garner some attention.

I believe this is the link you're looking for: http://talkfast.org/2010/07/23/a-cure-for-hacker-news-overlo...

It has rss feeds and twitter accounts for stories that get 20, 50, 100, or 150 points or more.

Seems like it hit the main page, so I'd say people like it.