Candidly, I feel sorry both for the authors and consumers of such books. I've written elsewhere, for example, here, about why "find your dream" career advice is largely snake oil. So I'll just touch on that here. Here's just one reason: The author tells what worked for him in landing a job and asserts it will work for the reader. The problem with that is that what works in landing a job for a person with the ability and perseverance to write a published book is unlikely to work for more typical job seekers.
For example, many articles and books have been published on how to land a job at Google. A Google search on the term "Land a Job at Google" yields 89,000 links. One of those links takes us to the book, Get a Job at Google: Craft a great resume, network effectively, and ace the interviews. Fact is, as the Wall Street Journal reports, Google receives 2,000,000 resumes a year and hires only 7,000 people. That's 3 out of 1,000, a far lower ratio than admission to Harvard. And many of those Google jobs aren't great---for example, screening those 2,000,000 resumes!
And most of the non-temp, interesting Google jobs go to people currently employed by a prestigious firm doing work similar to that in Google's want ad, with a strong recommendation from their boss, a degree with high grades from a designer-label college, who has been personally referred to Google's hiring manager. Like I said, "how to land your dream job" advice is pretty snakey oil.
Now, here's why I feel sorry for the authors of such books.
Many of these authors have the fantasy of becoming a regular on CNN or some such, or at least getting $5K-a-pop keynote addresses, $200-an-hour consulting gigs, and/or using the book to establish enough credibility to land a job they otherwise couldn't. With those fantasies as fuel, those wannabes spend a year or two writing a book, a fortune on their wardrobe, upping speaking skills, a publicist, etc., plus many additional hours or money creating and adding SEO-optimized, traffic-building, relationship-building content to their website, blog, Facebook, Twitter, and LinkedIn, plus in-person networking with people who can help flog their book.
Alas, unless an author is already a household name, he or she is most likely to end up deriving less net income per hour for all those efforts than if flipping burgers at McDonald's. It usually takes a year or three to realize they've been wasting their time and money. By then, they're in the unenviable position of having to convince an employer to hire them over job applicants with a more germane and recent work history. Or they have to somehow convince their parents or spouse to be their permanent cash cow.
I wish more publicists, book packagers, etc., and indeed screenwriting, acting, and voiceover, and art coaches, who make their living selling the dream to wannabes were honest with prospective clients about the likelihood of non-celebrities generating a sustained middle-class income from their creative output, and honest enough to ask such questions as, "Do you really believe your expertise is great enough to tout yourself to the world as being able to help the sorts of people who buy career-help books to land great work in this lousy job market more than the zillions of other books, coaches, workshops, TV shows, articles, podcasts, blogs, columns, etc., that do the same, often for free?"
Short of that revolution, I believe that especially today, with so much free content on the Net and the ease of self-publishing, the old advice to "write a book to become successful" is invalid if not an outright scam. And more broadly, so is the industry catering to artistic wannabes.