资料：Word of Mouth promotion is based on the principle of pull marketing. Word of mouth （WOM） promotion is based on the principle of pull marketing. It relies on the transmission of a positive marketing message from person to person through conversation or a personal communication such as email or text message. Pull marketing gets consumers to bring other consumers to the product. In contrast, push marketing uses above-the-line promotional techniques to put products in front of consumers in order to generate sales. Red Bull extensively uses pull marketing. This approach involves getting consumers excited about the product and conveying this excitement to their family and friends. It is also about trying to get coverage of Red Bull events in the press. This coverage can encourage consumers to find out more about the product. It helps to generate momentum, through creating interesting stories for people to talk about, which in turn help to create brand awareness and grow sales. The founder of Red Bull used pull marketing to promote his original product in the 1980s. He hired a Red Bull Wings Team to go out and talk to people one-to-one about the product. This helps to create consumer interest in the product. As people experience the drink and appreciate its qualities, they become advocates for the brand. They share their opinions with other consumers when they talk with friends. The promotion therefore creates a ripple effect. What may discourage the consumers to introduce the product to others?