[dang]

Hmm. HN likes substantive articles and dislikes sketchy tactics. Those two almost never conflict. When they do, though, we tend to favor the substantive article, which this one clearly is. It's an elementary tutorial, yes, but an unusually well-crafted one, and had it appeared on the author's website (http://apfelmus.nfshost.com/blog.html), there'd be no question.

Perhaps the positive reinforcement of seeing what actually works to get on the HN front page—solid content—will combine with earlier negative reinforcement—prior sketchy tactics have gotten this site penalized—to induce a change in behavior. I know that sounds unicorny, but the last time something like this came up on HN, a different site actually cleaned up its ways. Maybe lightning will strike twice.

[geraldoramos]

I am curious to know why this post was taken down. It was certainly a useful post that organically bubbled to the top as quality content. Can someone please provide feedback.

[dang]

It wasn't taken down. It was knocked off the front page by flags. My guess is that users feel the site is spammy.

By the way, one of several tactics that you shouldn't use on Hacker News is astroturfing. That (along with vote-rigging) are likely to alienate users and get your accounts, and your site, penalized.