Word-of-Mouth Marketing: An Integrated Model  Miroslav Karlíček * – Ivan Tomek ** – Miroslav Křížek *** Word-of-Mouth (WOM) has recently become one of the most frequently cited terms in marketing. It describes informal conversations and recommendations from current and potential customers about products and services. Due to their credibility, these conversations and recommendations have a massive effect on sales. For example, according to a McKinsey & Co. study, 67 % of consumer-goods sales in the USA are based on WOM [20]. People talk about food and beverages, restaurants, electronics, music, fashion, investments, travel destinations, movies, cars, health and other topics with their friends, family members, colleagues, neighbours etc. These product-related messages have a powerful impact on customer decision-making. They are highly persuasive, because they come from highly trusted and unbiased sources (i.e. “people like us”). A relatively large body of research suggests that in general, the impact of WOM significantly exceeds the impact of marketing efforts. If a product receives negative WOM, typically, it cannot be saved by marketing communications. For example, Hennig-Thurau, Houston and Sridhar demonstrate this in the movie industry. Based on their study, the marketing efforts of the studios generate only short-term success (i.e. increase the opening- weekend box office revenues of a movie). However, WOM (i.e. movie quality judgments by both general viewers and critics) is the primary long-term revenue driver [7]. Consistent results were also provided by the researchers Villanueva, Yoo and Hanssens [25] who examined the difference in the value of customers acquired by marketing communications and by WOM. Based on their research, marketing-acquired customers (i.e. customers induced by advertising and by direct mail) add more short-term company value, but WOM-acquired customers add almost twice as much long-term company value. WOM- acquired customers also generate further WOM and bring in twice as many new customers. Similar conclusions can also be found in the research study of Trusov, Bucklin and Pauwels [23] who proved that WOM has significantly longer carryover effects on customer acquisition than event marketing and media relations (21 days versus 3 to 7 days). At the same time, WOM produces significantly higher long-term customer acquisition elasticity (approximately 20 times higher than the elasticity for events and approximately 30 times higher than the elasticity for media appearances). The impact of WOM on brands is very strong. Organizations therefore try to stimulate positive WOM for their brands. These efforts, which are further supported by the decreasing effectiveness of traditional marketing communications, are denoted as “WOM marketing” or “buzz marketing”. The stimulation of online WOM is usually described as “viral marketing”.  This study was implemented in cooperation with the Outbreak WOM agency as part of the research programme The New Theory of Economics and Management in Organizations and Their Adaptation Processes (MSM 6138439905). * Ing. Miroslav Karlíček, Ph.D. – Marketing Department, University of Economics, Prague, miroslav.karlicek@vse.cz. ** RNDr. Ivan Tomek, CSc. – external cooperative of Marketing Department, University of Economics, Prague, ivan.tomek@mrthink.cz. *** Ing. Miroslav Křížek, Ph.D. – Management Department, University of Economics, Prague, miroslav.krizek@vse.cz.