Pros: Good simple lessons that stand the test of time. I appreciate reading a self-help book that isn't about manifesting. I will probably re-read this in a year.
Cons: Repetitive. There is one point where the author quotes himself from the start of the book.  The main take away is be nice. Stroke the other person's ego. 

i guess these are the principles of treating people which fortunately my dad has taught me about or showed me how it works. so this book is nothing other than a reminder on what to act, it doesn’t give you very particularly daily situations to think of, it’s generic in the business settings, and that’s pretty much a limitation because it doesn’t address the cons of such things, it hinders building rapports when you don’t talk about yourself, it means you need to hide yourself always to get along with other people, and by being so you’ll be popular, which is not very much the case in the 21st century when we actually like eccentricity. there’s not much argument going on, just some instances of being nicer to people, and just bearing in mind with this major principle may be more helpful than reading the book. it also doesn’t talk much about reciprocity and the downside of it, like what if you just don’t do this, does this make you a smaller person? these kinds of questions are unaddressed here, and therefore the credibility of the book is merely on the levels of manoeuvring through the adult world of relationships and how to be liked. the influence bits could be useful, but again i find the let other people be amused by your ideas cause you bring them up and get them happy about it highly manipulative, and it’s surely not helpful if the book falls into the wrong hands, just saying, alongside contradicting the genuine appreciation of other people and those kinds of principles in the first half of the book.