How Word of Mouth Works

Dicther (1966) was one of the first researchers who investigated the way word of mouth influences consumers’ attitudes and perceptions. He analyzed the psychological aspects of word of mouth: speaker motivations, listener motivations and influential groups.

Johnson Brown and Reingen (1987) examined, from an interpersonal network perspective, the role that tie-strength may play in WOM processes. They concluded that strong-ties sources such as close relatives or friends are from whom most people obtain information. They also claimed that the role of weak-ties sources is not as important as it was though.

Herr, Kardes and Kim (1991) investigated the mediation of WOM effects on consumer’s persuasion. They attempted to identify additional moderating variables which may influence the degree of persuasion of WOM on the audiences. The results of their investigation indicated that WOM communications often have a strong impact on product judgments because information received in a face-to-face manner is more accessible than information presented in a less vivid manner.

Dunhan and his colleagues (1997) supported the findings of Herr, Kardes and Kim and added new information about other factors which affect word of mouth communication. They concluded that the likelihood of choosing strong-tie sources is influenced by task difficulty and prior knowledge, and the likelihood of choosing weak-tie sources is influenced by the importance of instrumental cues and subjective prior knowledge.

Figure : General Model of Recommendation Source Choice

Source: Duhan et al. 1997

Word of Mouth

In 1984 Lazarsfeld, Berelson and Gaudet  stated, contrary to principal theories about mass media communication of the 40s, that the mass media has limited effects in the process of mass persuasion. These authors questioned the validity of “the bullet theory” or “the hypodermic-needle theory”. This theory predicts that mass communication messages have a strong and universal effect on all the members of the audience who are exposed to them.  They concluded that opinions and attitudes of individuals are rooted in the social spheres they belong, and mass media do not influence directly the audiences. In fact, they influence a reduced group of individuals (“influencers” or “opinion leaders”).They interpret the message of the mass media and spread it though their interpersonal relationships (two-step flow in the effect of mass media).

Lazarsfeld and Katz (1955) investigated the role of the personal influence in the daily household purchase decisions. They found that members of interpersonal communication networks (family, friends and colleagues) were the most important source of influence in the purchase of household goods and food products. They concluded that personal influence, which was called later “ word of mouth” by Ditcher (1966) and Merton (1968), was seven times as effective as newspapers and magazines, four times as effective as personal selling, and twice as effective as radio advertising in influencing consumers to switch brands.

Merton (1968) was one of the first authors who coined the term word of mouth communication. He defined this concept as a process of personal influence, in which interpersonal communications between a sender and a receiver can change the receiver’s behaviour or attitudes. The influence of personal sources as friends, relatives or colleagues plays a fundamental role in affecting perceptions and attitudes.