Opinions expressed by Entrepreneur contributors are their own.
Often described as the most powerful form of marketing, referred customers — among their many virtues — have no less than 25% higher profit margins than non-referred ones, according to a 2011 joint study conducted by the University of Pennsylvania and Goethe University Frankfurt. So, the number you can convert into customers or clients will measure the success of your business in a very real way.
But how to do that?
