Geoffrey A. Fowler, Washington Post:

I recently used my credit card to buy a banana. Then I tried to figure out how my credit card let companies buy me.

And:

Despite a federal privacy law covering cards, I found that six types of businesses could mine and share elements of my purchase, multiplied untold times by other companies they might have passed it to.

And:

When I swiped my cards, of course my banks received data. What’s surprising is who they can share it with. My data helped identify me to Chase’s marketing partners, who send me junk mail. Some data even got fed to retail giant Amazon because it co-branded my card.

And:

This is where the Apple Card is different. In the Goldman Sachs privacy statement, its answer to most kinds of sharing is “no.” Goldman still shares information with credit agencies about whether you pay your bills. But it says it doesn’t feed transactions to marketers or a sister company that mines card data.

The whole article is a fascinating read. But if I had to highlight a single point, it’s that last quoted paragraph above. Yes, you can get more cash back, more frequent flyer miles, etc., but there’s a price, both in a yearly fee charged by most credit cards, and in data sharing.

What’s in your wallet?