This paper points to the possible application of viral marketing as a way of promotion. Thanks to the rapid development of technology marketing has a tendency to increase itś possibilities. The beginning of the 20th century, television, radio and newspapers represented the dominant media in the purpose of promotion and marketing, but regardless of the dominance they showed certain deficiencies. These deficiencies have been remedied advent of the Internet as a new medium of promotion. From the very beginning of the development of viral marketing in the mid 90's of the last century promotional activities on the Internet have provided new opportunities for businesses, nonprofit organizations and other entities on the market to achieve new ways of two-way communication with consumers. This work focuses on the use of viral marketing in the purpose of promoting non-profit organizations through social media. Through the example of the campaign ˝Prekinimo šutnju˝ of nonprofit organization Roda this work is trying to get an answer to if this is a kind of promotion suitable for non-profit organizations and how it can be used with maximum potencial and minimum costs. Specifics of viral marketing are properties such as very low-cost, two-way of communication, speed of dissemination of information, faster and easier adaptation to new conditions and easier access to desired target groups. Social networks can be used to help consumers that they could easily engage in marketing activities and to thus gain public attention.