Comment by nerdponx

It can uniquely identify you, personally, danielvaughn, among a sea of millions of other "anonymized" users. That information can be used to provide precisely-targeted advertising -- or coming soon to a Kroger near you -- precisely targeted prices for products. And of course it's valuable to anyone who is interested in stalking or impersonating you and might be wiling to pay for access to that data, whether by insider leaks or hacking. It's your choice as to whether you personally care, but a lot of people do care, and the more people who don't care, the harder it is for those who do.