The essay concerns corporation?s usage and consumer?s attitude towards the phenomenon Big Data. The aim is to analyse whether corporation-management and future ambitions concerning consumer data coincide with attitudes and opinions of today's consumer, and how these opinions reflect consumer behaviour online. The essay is limited to focus on how companies use consumer data in order to better understand and improve the efficiency of their marketing. A self-composed analyse-model was created using previous studies concerning Internet-usage in Sweden, previous management analysis of corporations use of Big Data combined with theory of Cognitive Dissonance. A questionnaire was then created with the analyse model as foundation.