Customer evangelism is a new digital marketing practice that leverages existing happy customers to promote products and services to their social networks. As evangelists, satisfied customers engage in positive conversations to convert others. This organic word-of-mouth has been strengthened by digital platforms like Facebook and Twitter. Studies show customer referrals significantly increase purchase intent. Companies can encourage evangelism by making it easy for customers to refer products, being transparent about their identity online, and monitoring/participating in social media conversations. Measuring the results of evangelism tactics is important to prove their value.