It's a spam , even on reddit it is , the OP links to a page wide ad.. Want to promote a paid stuff ? buy an ad , just dont use HN.
I'm sorry, I did my research and found at least 3 ebooks linked on hacker news without complaints for spam, so I thought it was okay.
BTW, I would be also interested in a discussion about the sales page, copy, style.
I am a web developer, after all.
Indeed, there was "Designing Web Applications" by Nathan Barry for instance. See discussion at https://news.ycombinator.com/item?id=4909784 . Very similar discussion on pricing by the way...