[evdawg]

I find it completely and utterly mind boggling that anyone would find this useful. Spending habits are private: tracking your OWN is useful. But sharing everything publicly? It's insane. Guaranteed you are going to be embarrassed after you reveal your $200 purchase at the Love Shack or once your friends realize you eat at McDonalds 3 times a week. What happens people start tracking down gifts or you blow the surprise on your engagement ring?

People want to share some of the things they buy to show off, but no one wants to share everything they buy. From the mundane to the inane to the embarrassing, it's a wide window into your private life that very few would feel comfortable opening.

[randallsquared]

The article covers this: you register one of your cards, and use that for public purchases. They plan to provide a sticker for that card to make it more obvious.