Funny, I am currently listening to this book on Audible. A lot of people think that it's a book about manipulation but it's really not. It's a book about leadership through reciprocity. If you want people invest in your goals you have to contribute to theirs.

Win Your Case by Gerry Spence is also a favorite of mine of the same vein but applied to confrontational situations, but the advice are based on the same foundations.