A lot of theories and approaches regarding the very beginning of marketing. But, it might be the most universally to consider that marketing exist since the beginning of human race. Since ancient times, traders have used all available resources to attract people to themselves and their products and convince potential customers that such products are exactly what they need. Thanks to the rapid development of technology, after the second industrial revolution marketing takes on unimaginable proportions. Except for business purposes it has become the subject of scientific researches. Television, radio and newspapers are the media which are fully developed in the 20th century. However, regardless of their dominant presence, they had certain disadvantages. From the point of marketing, limitations of those media are removed by the advent of the internet. Considering the growth rate of the number of web users, it is just a matter of time before half of the world's population is online. Sucht trend received a very good response from marketers. With the Internet gradually taking over the media landscape, television and radio have remained present yet they have lost the importance they once held. Things have changed considerably, especially in the form of communication with the advent and growth of the number of users on social networking. Faster transmission of informations, content sharing, two-way communication (further supported by mobile technologies) are just few of most important benefits over traditional technologies. The viral marketing was created which is partly considered to be the successor of guerrilla marketing as a result of that. Both cases are about unconventional approach, there are some differences between them. A viral or virus marketing is a powerful tool in advertising. Unfortunately, there is no recipe or a strict rule which ensures that message will spread with a quickly in a short time. There is example of the Melbourne Metro Trains which shows what a successful advertisement campaign looks like and analyzes the aftermath of the publishing of the campaign video on YouTube that has collected over 100 million views. Mentioned elements have strong, almost persuasive effect on visitors. In thesis are also mentioned internet meme as a form of virality, their specificity and application options for marketing purposes. Finally, there are presented few scenarios of further development of technology and other factors that are expected to provide an additional contribution to achieving virality of campaigns in the future. The thesis will present the concept of viral marketing and provide informations for developing readers own opinion about theme.