Driving word of mouth has long been the secret sauce coveted by brands. The experts agree; it’s the most effective form of marketing. It’s also the most evasive to grasp, to promote, to control, and to optimize. At a time when everyone’s customers are more connected than ever, word of mouth has changed from a ‘nice to have’ to a necessity for growth.

To help you maximize the return on investment in your referral program, we’ve collected the top 10 ways to test and optimize refer-a-friend for your brand.