The book changed my life by pointing out the value of focusing on other peoples' interests, concerns, and motivations instead of my own as a fundamental principle in advancing ideas and accomplishing success. One of the most memorable suggestions was, "Be hearty in your approbation and lavish in your praise."
While acting on the book's ideas required working hard to become more outgoing in new interpersonal situations (something which has taken years, and is still an ongoing effort), Carnegie's emphasis on listening to others played to an introvert's strengths. All of a sudden a situation that seemed hopeless became very much in reach to start improving right away.
My recommendation to you? If you've never read "How to Win Friends and Influence People," get a copy and put it into action. Although it's decades old, it's a fundamental handbook for creating successful, important relationships. And for me, I'm going to review it as a refresher for both IRL interactions and to consider how I am doing in translating the ideas into the social media world. - Mike Brown