The most extended way to get benefit from personal data is based on permitting users to access useful contents, applications, and services for free, and they in turn allow these platforms to make use of their personal data in income generating activities, like, for example, personalised publicity, profiles selling, etc.
Another possibility is that in which users are who exploit their own data either directly or through an intermediate agent, Data Broker, who interacts with the market. In this case, each user decides what information to share, and the market decides how much will be paid for that information.
The first model is, so far at least, few transparent, and we are not always aware of what information of us is being collected, while in the second case, each person chooses what to share and who it is shared with.