Don't get hung up on data = a specific person.

Put the biggest filter you can find into the system, so data doesn't equal a specific person.  Use zero knowledge proofs so that all you can tell is crypto transaction, $15, at x place and at y time. That's the most valuable part of the transaction.

Holding personal data is a headache and generates regulatory issues.  Don't want it. Don't want it. Don't want it.

I've said it many times before. Personal data: Don't want it.

People that buy this type of data don't care about tracking down individuals to sell them a can of beans.  

Roger Ver should be walking into Starbucks, right about now...quick, go there now with large pack of washing tablets and a 15% coupon....

Of the $1bn spent in Star City last month; 10% was in that area; 5% was over there outside that mall; 30% was over there between the hours of 8pm and 3am; etc.

Right, lets get our marketing strategy right so we can advertise where most people buy xyz; lets make sure we're stocked up with xyz during 8pm to 3am; etc.

See, anonymous data can be really useful and valuable.

edit

And.....it is very on point:  http://www.comsoc.org/netmag/cfp/mobile-big-data