Evangelism marketing is when companies try to get existing customers to spread their message and talk about their business to others. It's kind of like word-of-mouth marketing except companies don't pay people to do it. Instead, they try to make the product or service so amazing that customers feel inspired to spread the message. For example, a company might create a great product that people love, make sure their customers have a great experience, or offer some kind of unique benefit. By doing this, customers become excited about the product and think of it as something special. They start telling people about it, which increases the company's reach and often leads to more sales. It's like having friends tell you about a cool restaurant - it's a lot more convincing than hearing a commercial.