The exact way you do these things depend on the culture for sure, and the book is written by an American. From what I understand Germany is less directly "friendly" than the US so the pleasantries may not carry over, but I have to imagine that considering the other person more than yourself does carry over.
American here. I’ve found that the friendly “American way” of doing business lets my team seal deals faster than their European competition. I initially got pushback from my UK team. “That isn’t how it’s done.” But human nature is human nature, and taking people’s personal aspirations into mind is never a bad strategy.
You won’t be able to run a business the American way in Germany, not would you be able to it vice versa.
Nor you should be able to be.
(There is nothing historic about being able to capture 20-25% of the world’s GDP either — England (1800s), Turkey (1600-1700) and China (European dark age through Middle Ages) has all achieved the same economic power US enjoys as of today.
This thread is incredibly vague. I bet there is significant if not majority overlap between the two.
Back to Dale Carnegie, his advice about not telling people "you are wrong" and getting to know them is some of the best and simplest advice I've ever received, and transcends time and space.
I found it's study of status quite good. So much can go wrong for people when they fail to maintain a harmonious exchange of status when interacting with others. This book describes how important status is in comedy and breaks down some old Marx brothers skit to analyses the humour in seeing somebody have their status diminished.
It's been a while since I read it, but it's stuck with me and I remember developing a new sort of awareness of my interactions with others.