Buzz marketing in social networks is often seen by announcers as an opportunity to reach the biggest audience. However, the risk of failure of buzz campaigns proves not to be negligible and its consequences may be serious for the company. In order to succeed in such buzz campaigns, this research study focuses on cultural aspects, and more particularly on the central role of cultural congruency. To explore these aspects, a qualitative study, based on 36 face-to-face interviews with marketing professionals/advertisers and consumers, has been carried out. The results highlight the importance of cultural values for consumers in Arab-Muslim countries, especially when buzz marketing campaigns touch the taboos. Terms used in the advertisement are also decisive in the success of a buzz campaign.JEL classification: M30, M31, M37, M39