I'm sure this is interesting, but I'm not sure if it's "$6 + automatically renews into a small print $40 annual subscription in six months" kind of interesting.
It's not the only article they published this month though. They had to do hours of research, writing, editing, etc for the article, their labor is worth money. Whether you think it is, or whether you want this particular content, is a separate matter though.
Oh sure, but a link to a story on Hacker News that you can only read once you pay money is just an ad. It's not wrong to put useful ads on Hacker News, but they should be labeled.
