This isn't normally my thing to post about something but I in the name of helping my fellow salespeople, this needs to be said
Before you buy a book that "teaches you to sell"...specifically this book, you should probably consider the source first. Did Jordan Belfort make a lot of money in sales? Yes...100% The question you should be asking is, how? This man is celebrated for deliberately lying to and cheating clients out of millions of dollars (and doing prison time in the process). The sales cycle is easy when you can promise the world ...where it gets tricky is delivering on those promises. I'm sure there are some take-aways here for sure however, I wouldn't buy water from this guy if I were dying of thirst in the desert...much less his book. His movie and biography should make you feel the same. If you are looking for entertainment...by all means buy the book. If you are looking for guidance to become a better salesperson, there are plenty of other reputable people that have made it in sales the right way, willing to share their information.
Speaking of free advice, here you go - Work hard and solve your customer's problems
Good luck and happy selling!