I saw @grantcardone on one of @garyvee's shows a few weeks back promoting this book, and I've seen him referenced a few times when people are talking about sales, or cold-calling.

Any particular reason you can give as to why you recommend the book? Like, apart from Grant being an awesome, successful dude, what's the underlying theme to the book? What's the one thing in it that really changed the way you think about sales/etc?