This will also help the identity thieves to rob you blind, and then some.

There'd be no benefit to the issuers of the cards, and the existing system is so embedded that it would involve major transition costs. And the benefit would be minor. So I can't see this happening.

There would truly be no incentive for the stores to participate, it's all about brand loyalty and the stores want their own systems and their own cards.

I think the value in this idea lies with who is aggregate information can be used/analyzed. Typically the more we know about a select customer's buying pattern, the better we can understand their purchasing patterns.

If I know that Suzy Q buys a certain type of shoe (color, material, heal height) and I sell clothing, I'll match the right clothes to her recently purchased pair of 4", satin red stilettos and reach out to her with "instant options".

Instead of viewing this through the eyes of the consumer, think about the supplier ... or better yet the physician who can tell how many times you've been to McDonald's vs. the local salad bar.

Info is power ... if we know how to slice and dice.