>Traditional stores are not going to send each other your transaction history to build a profile of interest and personality, and each store won't have a complete enough history or even the expertise to mine it.

"Traditional" as in "before the age of Amazon"? They do, through store rewards cards. Harris Teeter knows what I have bought and has figured out what I only buy on sale, Target can identify pregnant women with stunning accuracy, and I'd be surprised if other retailers didn't do similar stuff. You're probably thinking of independent/mom and pop shops.