In this final postgraduate thesis, the field of word of mouth or word of mouth advertising is analysed and how this type of advertising can be implemented in micro and small enterprises. In the introductory part of the paper, the motive, objective, and goal of the paper are explained, the methods and sources of data collection are stated, and the content and structure of the paper are explained. The second part of the paper uses a review of and scientific and professional literature to explain the concepts of enterprises, entrepreneurs and specifically micro and small enterprises, the application of marketing and challenges for micro and small enterprises. Through evolution and definition, the classification of micro and small enterprises is presented, and by presenting the challenges of the work it aims to point out on the needs of use of promotion, accurate use of advertising and especially advertising by Word of Mouth for business success. In the third part of the paper, with the help of professional and scientific literature, the Word of Mouth is analysed and its origins, what are elements of Word of Mouth, but what efforts can be made to initiate Word of Mouth. Initiatives and tools that can initiate Word of Mouth are explained here. The application of NPS® measure or Net Promoter Score® with Innovative question of customer intent for word of mouth, is explained in the main part of the paper, as well as the way Net Promoter System® is implemented in the company and the benefits of application. The subject of this paper is to investigate how Word of Mouth can be encouraged in micro and small enterprises. The indicative research was conducted by the method of testing on a sample of 150 respondents by e-mail. Consumer attitudes and opinions on Word of Mouth, reasons, and readiness of consumers for word of mouth were examined, and to determine whether there is already a presence of word of mouth about micro and small enterprises. In the conclusion, the author's concluding thoughts on the subject are presented, as well as assessments of the importance of word-of-mouth for micro and small enterprises and how it can be initiated by the micro and small enterprises.