In the contemporary globalised markets opinion leaders play a vital role in the process of the purchasing decision-making of consumers. Thanks to their individual skills, specific knowledge or their personality, opinion leaders have a direct or indirect influence on the attitudes and decisions of consumers. In the contemporary globalised marketing using social media, this role is taken over by the influencers who affect consumers with their thoughts, attitudes and opinions and thus, significantly influence trends in demand for particular products. Over the recent years, influencer marketing has become increasingly popular, representing a specific type of social media marketing. The aim of this scientific contribution is the systematization of knowledge about the position and roles of influencers as opinion leaders in the social media environment in order to identify their typology, influence factors and the intensity of their impact on consumer decision making process, based on the comparison of knowledge from the results of global research studies and the quantitative online research study processed by authors. The findings of the survey showed that the promotion of some products through influencers may be more advantageous than others. Influencers will have the greatest impact when buying clothes, shoes, cosmetics and, surprisingly, services. Meanwhile, people rely heavily on other factors to buy food, jewellery and electronics, but it is not excluded that influencer marketing could affect them as well.