How about a world where you swipe for a Big Mac and then the next time you go online you get an ad for Slimfast? That’s the big idea behind Visa and Mastercard’s new business foray: selling off all your swipe data to online advertisers so they can more precisely target their ads to what’s going on in your skull. It’s another nail in the coffin for the quaint fiction we call “online privacy.”

The WSJ reports that they saw a document MasterCard was pitching around earlier this year. It described how the company wanted to sell cardholder data so each person could be targeted with ads online based on their individual swipe history.

The company has since walked that back after they realized it would break rules about how financial-services companies can use their members’ data. Now MasterCard and Visa have moved onto an idea where cardholders are anonymized and aggregated into various “buyer profiles” that can be sold to online advertisers.

In a related move, Visa has also filed a patent for a system that would mesh information from DNA databases into buying profiles for targeting ads online.

MasterCard lets people opt-out from these kinds of programs by filling out the info at http://www.mastercard.us/privacy under “Data Analytics Opt-Out.” Visa doesn’t offer any such specific web page.

Using Credit Cards to Target Web Ads [WSJ]

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