This Master thesis studies the reasoning of users towards the monetization of their data as part of social networking sites’ (SNS) business model and takes into consideration the ethical dimension of businesses. As the Cambridge Analytica Scandal highlighted, people are concerned about how SNS use their data, especially when third parties are involved. To study our topic, we investigated it into three sub-purposes: first of all, we aimed to get a deeper understanding about how people use and perceive Facebook. Then, we searched information about how people think and reason regarding the current offer about having a free registration while this involves giving SNS private data. This system may raise corporate ethical questions from a consumer perspective. Finally, for the third sub-purpose, we looked at the users’ attitudes and behaviors towards Facebook’s data monetization.   This study was conducted using a qualitative method. We opted for three focus groups gathering four to five people each to understand how people interact to each other’s responses and arguments about the six core questions we asked them, letting concerns and argues take place. By conducting focus groups, we were able to get a deeper understanding about people’s reasoning regarding the data monetization of their own private data but also how they might react if an alternative to Facebook would emerge. To analyze what has been said during the three focus groups, we used a thematic network analysis and generating four main themes: users’ perception and use of Facebook, users’ understanding about data monetization, users’ attitude about this aspect of Facebook’s business model and finally users’ behavior. We found a behavior-intention gap. People are actually aware of the data monetization of their own private data but that scandals do not affect their behavior as they keep using Facebook. However, they started to minimize their use of Facebook way before the scandal because of the data monetization. They consider the corporate ethical consideration as an important insight while using a SNS and could leave the social networking site for another one, if the network effect was not so powerful.