How is this different from many of the other posts that are book shills? I reckon there's at least one post a day on the front page. It's not fair to call it o

How is this different from many of the other posts that are book shills? I reckon there's at least one post a day on the front page. It's not fair to call it out when shilling is tolerated on HN, simply because you didn't like the article.