The main topic of this paper is data-driven marketing, which is implemented in various types of industries today. Its specificity is that it is based on customers' data which is collected through devices, website visits, and various transactions which makes those data become big data over time. As a result, precisely from that specificity of this marketing field, come problems with its implementation. However, there are also visible benefits for the company, if the implementation was successful. The paper is both about advantages and obstacles that occur during the implementation of data-driven marketing and about the ethics of that same implementation. Legal boundaries around the use of other people's data and laws which protect consumers have been examined. At the center of this paper are the consumers themselves and their perception of interaction with brands, and also the characteristics of that interaction. Moreover, the goal of the paper is to examine the trust level of young consumers toward brands and how informed they are about the ways their data are being used. As a part of this paper, quantitative research via questionnaire has been conducted on the student population. Its objective is to examine young people's familiarity with both positive and negative outcomes of giving their data to brands, and their perception of the interaction with brands.