I'm not suggesting it's an ad in the sense that someone paid Pollan to write this article (other than the Times), but the article linked is not a discussion of the title; rather, it's a suggestion to the reader that should they find the subject matter interesting, the book would be a great place to learn more.

I will admit to a certain bias in placing reviews on the mental shelf next to certain forms of advertisement (I doubt the author purchased his copy of the book), but I am not trying to project that view onto anyone else.