Add to ORKGThe primary aim of this bachelor thesis is to analyze some viral factors of the chosen viral campaigns from the Czech Republic and also from the rest of the world. The assessment takes account of the acquired theoretical knowledge about this issue from the first part of the work. On the basis of these facts is recorded the development of the viral marketing which has changed a lot recently. Especially thanks to a spectacular arrival of social networks, as one of the most used medium in the world. The secondary aim of the work is to give every reader some new information about idea of "viral marketing", as one on the most recent trend in the sphere of Internet marketing. And of course broaden the people's awareness of this tricky but very ef...