The bachelor's thesis is dedicated to the in-game marketing: marketing in digital games. Apart from usual mechanics, such as microtransactions, monthly membership payments, paid downloadable content or in-game advertising this thesis describes the game as a marketing tool and problems related to cybersecurity and persuasive microtransactions. The theoretical part contains recent and distinctive examples of described mechanics. The thesis also contains the evaluation of the questionnaire research in which 409 gamers from the whole world took part and which aimed on gamers' view on in-game marketing and their buying behaviour. Even though the demography of respond...