Marketing has significantly changed during the last years, due to the evolution of the World Wide Web. Nowadays, it is much easier to reach the desired audience, at the right time. When thinking about the means of mass communication, such as newspapers, radio broadcasting and television, which have been present in our lives for many years now, there come some very relevant marketing-related questions: who is a company actually targeting through its mass communication campaigns? How can it know if the targeted consumers have seen the message or have payed attention to it? And, most importantly, how can a company measure the impact of its mass advertising campaigns?