[Porsche-O-Phile]

I'm not sure how you wouldn't be. Apple is brokering the transaction and even if they're not privy to the more specific details of your transaction (what exactly was bought, etc.) they certainly are tracking where and when you were when you used the service. It's not hard for them to figure out if you were in a particular store and used it what your preferred shopping habits / routines might be. Valuable information to profiling companies. If you use it at a particular place a lot or according to an identifiable pattern a lot of inferences can be made with startling accuracy - not much different from what a lot of retailers do now with CC transactions.

I personally can't stand big data and I hate profiling. I hate every damn thing about it but I dislike the inconvenience of dealing with cash transactions more - for now.