matas
I mean it's a very good book if you only want to get money (maybe) in your life and boost your confidence in your sales pitches. Otherwise, it doesn't seem to offer much content other than the anecdotal evidence for his claims.
And even that evidence may not be real as Napoleon Hill is generally regarded a con artist, he can't even prove he met most of the people he claims to. (https://en.wikipedia.org/wiki/Napoleon_Hill#Controversy)