Napoleon Hill actually talks about it as the habit of performing more serivce than paid for.
What he means is the habit of going above an beyond. Doing more than your actual job description and doing your job better than expected allows you to build a reputation as a good employee. He calls it the Law of Increasing Returns.
In my garden I always reap more than I sow. Every individual seed or seedling will produce more vegetables than that original see came from. Of the hundereds of seeds in a tomato each seedling will produce hundreds more.
That is what is represented by this Law. When Henry Ford set his $5/day minimum wage this was more wages than the average person was getting in a factory at that time. But he got more service and better service from his employees because of it. (Amazing to think that today we are starting to set minimum hourly wages at 3 times that amount.)
An example for today are stores that have return policies on goods with no questions asked. This type of thing spreads Goodwill that brings in more clients or customers.
The concept is to make yourself so useful to your employer or customers/clients so they wouldn't think of anyone else for the job or service. Sometimes you just need to do things without expecting payment. This is not the "that's not my job..." mentality.
"Render service to at least one person everyday, for which you neither expect or accept monetary pay." Napoleon Hill
Take the initiative, follow it with agressive action and do more than you are paid for. You need no ones permission to do this. Hand out a free coupon/gift that gives your client/customer one thing, but then offer an upgrade for something even better and see what you results are!
Paula J. Kaprocki, LMT, BS, CPC
Life Coach, Massage Therapist, Infinite Possibilities Trainer, Author