05/21/2014 02:16 pm ET Updated Jul 21, 2014

Will Trade Data for Food

Milton Friedman, the famed University of Chicago economist, wrote, "There is no such thing as a free lunch." But in a Weight Watchers cafe in London, England, diners are promised "free" meals in exchange for their posting about the experience in social media.

So is Friedman turning in his grave? Not necessarily.

The meal isn't free as people are exercising free will in trading off their personal information for the food. Those diners who participate in this exchange are bartering, openly, their personal data for something they value -- in this case, food. So Friedman, market-based economist, might really like this concept.

Would that similar use of peoples' data shared online be given the same transparent, value-exchange treatment.

As we self-track with digital health devices, check in via FourSquare in the bar where we're meeting up with friends, enjoy benefits from retailers' loyalty cards, and fill prescriptions at the pharmacy, our individual "small data" are getting mashed up with others' daily data exhaust in a world of Big Data.

We might be very happy to trade data for food in a transparent market where we give something and get something back that we want. But in the more opaque Big Data world, trading data for something of value isn't very clear, and more often than not, we're not offered anything in exchange for an asset people don't yet fully recognize as a personal asset: Our data that we create every day if we use a credit card, an online social network, or a digital device with an app.

Most people in the U.S. are familiar with the FICO Score: When we apply for a home mortgage or for a car loan, the FICO score is what the lender uses to assess our credit-worthiness. That score is an index made up of many of our personal numbers, such as the number of credit cards we hold in our name, the amount and frequency of credit card transactions, our timeliness in paying bills, and outstanding loans, among other personal financial characteristics.

Increasingly, those numbers are being mashed up with newer kinds of data: social network information that we leave on Facebook, the 140 characters we type into Twitter, and retail purchase data that third party data brokers collect on us in loyalty programs at grocers and department stores (think: Target). Our phones' geo-location trackers follow us around, 24x7, and know more about whether we're depressed and anti-social (when the phone is home with us for days in a row) than our doctors or family might realize.

Trading data for food is a fair deal for people making a conscious decision to write about Weight Watchers' pop-up store experience -- the cuisine, the camaraderie, the social support for choosing healthy food, the great service. Trading data in the dark for third parties' profit -- without cutting us into the value created in the Big Data mash-up. That's a very expensive lunch indeed.