Idea is very interesting and smart but I don't think people want to sell their data consciously. If Facebook get our data without our knowledge, it's kind of like acceptable but I don't think people push button to give away our data. It's a huge cognitive hinderance. And data can have value only when the volume is big. Since each data(small datasets) has almost zero value, i don't think it's expensive/attractive enough for us to push the button to sell it.