The premise of both books is that the key to career happiness and success is not to improve your weaknesses, but to build on your strengths. To build on your strengths you have to know what they are, and they just happen to have this handy test on the internet to find them for you. You basically buy this book if you want to take the test (each book has a unique password for getting into the test website)
That's about it. About half of both books is nothing more than an appendix defining the 34 "strengths" they list. In the case of the sales version there are some chapters on "sales" and "sales management" which don't have anything earth shattering other than stressing that improving weaknesses is sure way to career misery and building on strengths the way to go.
The test is analogous to Meyers Briggs in that it requires you to sit down for ~25 minutes, go through questions, and presto your personality is laid bare for you. The basic premise is that these strengths are "hardwired" during our formative years and therefore can't be changed. And since they can't be changed, why fight them? My strengths came out as:
I guess that sounds like me. But like a horoscope, the descriptions could sound like anyone in the right situation or mood. My top one, Deliberative, is described as:
You are careful. You are vigilant. You are a private person...You sense many risks (and) draw each one into the open. Then each risk can be identified, assessed, and ultimately reduced. Thus, you are a fairly serious person who approaches life with a certain reserve.
Isn't everyone like that at times? Or is it just me?
The main problem about the test is that once you have these strengths, it doesn't really say what you should be doing. The Sales version has examples of happy sales people for each and every strength, just different kinds of sales (for example I should be doing strategic sales with a small number of large, unchanging accounts - which is what I do), but it doesn't say what other sorts of careers that I might enjoy (not that I want to change, but I am curious).
The other problem I have is that the test web site has lots of come-ons for more books, "personal sessions" and the like. Essentially the are using both books and the test as an entry-level advertisement.
So I would give this book 2.5 stars out of 5, more if you are really into self-testing. If you want to save twenty bucks, Meyers Briggs tests are out on the web for free.