On the corporate side, the upshot of our data (the benefit to us) isn't all that interesting unless you're an economist. In theory, your data means ads are better targeted, which means less marketing spend is wasted, which means lower prices. At the very least, the data they sell means you get to use genuinely useful services like Facebook and Google without paying money for them.
Christian Rudder, Dataclysm: Who We Are
data, marketing, privacy