Note that unless you're explicitly blocking it — you're giving away much more information when you shop online than with facial recognition in a physical store.
I'm not sure that's true -- cameras can track you around the store, seeing how long you linger at each product display, recording every time you reach out to touch a product. Which seems similar to the information online merchants can collect.
One thing they can collect in the store that they can't as easily track online (unless you're sending product links around) is who you are shopping with -- they can see that you come to the store with your friend, spouse, or children.
Google/Facebook and others know how long you look at a specific post/ad/video/etc and knows who you're with, even when in a private residence.
If you're in someone's house on their wifi network and they're shopping for socks... you might start seeing ads about socks. It's way easier to track this based on network information than creating facial recognition databases.
A lot of the "Facebook is listening to your conversation" fears stem from the fact that people don't realize that they can use data to make connections like this.
If you're remotely concerned about privacy, at the very least Facebook should not have an app on your phone (Google's doing it too).
I'm not sure that's true -- cameras can track you around the store, seeing how long you linger at each product display, recording every time you reach out to touch a product. Which seems similar to the information online merchants can collect.
One thing they can collect in the store that they can't as easily track online (unless you're sending product links around) is who you are shopping with -- they can see that you come to the store with your friend, spouse, or children.