Does they keep In confidentially our own data? (like name, second name, own info from social network)?
During the final stages of us processing your data, we are going to anonymize it. That means this sort of information will not be present in the final analyzed data batch that we are going to be selling. So you don´t have to worry.
When you say 'anonymize', do you mean all personal data like age, sex, location will be removed from the equation or do you mean, it will be anonymized on the count that it will remove the name and be clubbed along with data from other people into a category of people?
Probably just name and surname will be removed, because such factors as sex and age are usually pretty significant in various researches.