Evan Schuman's StorefrontBacktalk

For years, conventional wisdom about privacy has been that shoppers—especially younger shoppers—have been consistently sharing more information online to the general public, a trend that would likely continue as privacy desensitization progressed. But a report released Tuesday (March 5) from Carnegie Mellon University found the opposite when it tracked 5,076 Facebook (NASDAQ:FB) users from 2005 through 2011, one of the most extensive studies of social media privacy yet.

“Over time, Facebook users in our dataset exhibited increasingly privacy-seeking behavior, progressively decreasing the amount of personal data shared publicly with unconnected profiles in the same network,” the CMU report said. The implications for retailers are stark, suggesting that many of the privacy strategy underpinnings on both retail and e-tail may be flawed.

The report also found that those same consumers started sharing more information during that period, but only with people they assumed to be in a private group. And that sharing was expanded “both in terms of scope and amount of personal data.” For retailers trying to extrapolate insights from this report to apply to chain CRM and mobile programs, these two conclusions are frustrating. Is public data comparable to posted comments on sites? And private data to answers shared directly with the chain? If this private-vs.- public privacy psychological dichotomy also plays out with shoppers, how would it impact shopper feelings about mobile tracking?

What does this all likely mean for retail? First, consumers are sharing more personal info overall—which is good—but they are decidedly not doing it because they have become desensitized to privacy in general. If that was the case, the study would have found an increase in public sharing and it, in fact, found the opposite.

The increases were with so-called private sharing. And with Facebook—and many other social sites—the definition of private is light years removed from what the dictionary considers private. Friends lists on Facebook can often move into the hundreds and many lists easily top 1,000. (Full disclosure: Please don’t ask me how many of my LinkedIn connections are people I actually know. It’s a touchy subject.)

And those increasingly large amounts of disclosed private data are not merely shared with that battalion-sized group of intimates. That data also is shared with, as the report notes, “third-party apps, advertisers and Facebook itself.” And there’s no practical limit on who Facebook will choose to share it with. Contractors? Partners? Random winos?

This suggests that shoppers put a great deal of faith in promises of privacy, even when those profound pretend privacy protocol promises are impressively not private. Hence, privacy policies need to be properly prominent.

This report truly reinforces what privacy officers have been arguing for years: Shoppers will share an awful lot, as long as at least a half-hearted effort is made to indicate that the data won’t be shared with anyone, unless there’s a critical business need to do so, such as if someone offers us a couple of bucks.

The most over-the-top experiment with social retailing was likely Blippy, a site that told everyone what a specific shopper was buying. That move was initially applauded by some retailers, until Blippys imploded in 2011.