Orison Swett Marden 
Cheerfulness as a Life Power 

In Cheerfulness as a Life Power you will learn just how valuable happiness is. Happy people live longer, they get promoted more often, and they make more money. This book will show you how to be happier in your life, and more importantly how to use that happiness to be more successful. First comes the happiness and then the success, not the other way around as we so often think.