There's a powerful new player watching what you buy so it can tailor product offerings for you: the bank behind your credit or debit card.
For years, Google and Facebook have been showing ads based on your online behavior. Retailers from Amazon to Walgreens also regularly suction up your transaction history to steer future spending and hold your loyalty.
Now banks, too, want to turn data they already have on your spending habits into extra revenue by identifying likely customers for retailers. Banks are increasingly aware that they could be sitting on a gold mine of information that can be used to predict — or sway — where you spend. Historically, such data has been used mostly for fraud protection.
"Ten years ago, your bank was like your psychiatrist or your minister — your bank kept secrets."