[tbirdz]

If it has value on its own without the paragraphs about buying his book, surely it would have just as much value if the author moved the final paragraphs to the front, and clearly identified it as an advertisement for his book. The fact that he did not do that indicates that he thought less people would read it if they knew it was an advertisement right from the start. So then the author thought he would have to trick people if he wanted to get them to read the advertisement, so he sneaked it in at the end. This intent to deceive is what I am calling unethical. Now, sure this could be an effective technique, but the kind of deceit and trickery usually involved in such marketing leaves me with a bad taste.

[mindcrime]

The point is, there isn't a binary distinction between "it's an advertisement" and "it's informative content". It's a legitimately informative and interesting article, whether or not he mentions his book. So what difference does it make if he mentions the book at the beginning, or the end, or not at all?

And putting that stuff at the bottom has nothing to do with being tricky, or sneaky, or unethical. It just makes more sense to mention the book after the author has demonstrated some credibility through the content in the earlier part of the article.

[verisimilidude]

The message, whether informative, promotional, or both, ultimately needs to reach its audience. On both counts, this article failed to reach tbirdz and likely many others.

It wouldn't have been too much trouble to bring those skeptics back to the conversation by adding a short disclaimer closer to the beginning of the article. So why not do it? If the article is going to be both informative and promotional, some will want that expectation to be set right from the beginning. And if the informative bits can stand on their own merit, there's no risk to the promotional side in adding the early disclaimer. (IMO, it's not an unreasonable request, and not without precedent.)