I've got mixed feelings about that. If you spend with plastic (which most people do most of the time) then all your purchasing is trackable already. And frankly, I wish I could get my receipts in a standardized electronic format - my bank statements tell me where I've spent money, but not what I bought. Retailers have that information about me, but many don't share it electronically.

For example, my wife and I both like cooking and after we got a house we have almost stopped eating out because we were having so much fun in our own kitchen. With $20 of ingredients and our cooking skills we can whip up a meal that would have cost us most of $100 in a restaurant. There's an app/website where we can control all our grocery coupons from the local supermarket and make our shopping lists, which is fine, but we can't look through our previous purchases that way. I can scan and OCR the receipts easily enough, but that's a waste of my time. So I look through the paper copy, but I'm missing out on some useful longitudinal data.

In Europe, by contrast, privacy laws mean you can ask any company to hand over the data they keep on you to peruse it for yourself. At present this is viewed as an administrative burden but it has the potential to add tremendous value for consumers if implemented right.