Happy to hear (with Postgres or Python or Django) how you are going to filter out irrelevant comments, from comments mentioning books. And then how you're going to extract the book title and its author from a comment?
That doesn't look trivial at all to me... but... if you did that, please share with us a Github repo.
The site is http://hnlikes.com/ and on the About page I describe how it was done.
Like I mentioned it only looks for books that are linked (or videos, arxiv papers, Wikipedia etc.). I then use the link to get information from the site itself.
I calculate scores for the given link weighted by a number of metrics.
I'm sorry if I gave the impression this was fancier than it actually is.
That doesn't look trivial at all to me... but... if you did that, please share with us a Github repo.