Word of mouth basically involves the passing of information from person to person. When word of mouth is used by brands to communicate their message to the consumers, it is known as Word of Mouth Marketing or WOMM.

Word of mouth marketing is a form of marketing where consumers are in control and marketers participate to influence and accelerate the marketing message. WOMM is derived from Word of Mouth (WOM), the oldest form of advertising, in which people are providing information and making honest recommendations to other people about a brand, product or service.