I too read the book in my younger years, and it helped me a lot with making friends and my career. However, the book itself is filled with some terrible advice for communicating with people. I realized that as an older person. But as a young person it filled me much needed confidence. Like many of these books, the actual advice is crap, but I think it gives people the confidence they need to change something in their lives they are not happy with.
I highly recommend the podcast: If Books Could Kill. They have an episode on this book.
As someone who has listened to this If Books Could Kill episode and read the actual book, I think the podcast is mostly looking for problems where there aren't any. Despite the book's sleazy title ("influence people") it's mostly just basic, innocent social advice.