This ties in nicely with a few different things, such as Google Opinion Rewards in which you answer a couple of questions and get Google Play store credit. The surveys are infrequent but you're still trading data for credit.

Haggling for your personal data has also become a big part of the NCAA college basketball tournament with this years Warren Buffett / Quicken Loans Billion Dollar Challenge. This goes as far as giving a billion dollars for a perfect bracket, and I believe $100,000 each to the top 20 people. But look at how much personal information everybody that enters is giving away in order to enter:

"Any time you have self-reported data where they fill in their name and address and phone number, email, do they have a house or not, what's the mortgage like, are you looking for a new house, it's extremely valuable," Gupta says. "It's all opt-in at that time, and that's where the value is."

Then factor this by an estimated 9+ million people.