Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Taught Me the Most Important Predictor of Success... Enthusiasm!

Sales books should all deliver one thing: yield a positive return on your time invested in reading the book. In other words, if you make $8/Hr flipping burgers, then the 3-4 hours it would take to read this 190-page book would cost approx. $30 of your time. The first chapter alone will yield a return far greater than this $30 break even point if applied over the long-term, yet saying you will be more enthusiastic in everything you do is easier said than done, right? Fast forward to the last chapter, and the author sets up a nice primer to the teachings of Benjamin Franklin, who developed a "scientific method" to achieving this one critical goal. That's the secret to Frank Bettger's whole recipe for success as a salesperson in a nutshell.