Personalizing is fine. If I buy a bike from your store and then return, then I’m happy to see you say “how is your bike? Want to buy these cool wheels? They’ll

Personalizing is fine. If I buy a bike from your store and then return, then I’m happy to see you say “how is your bike? Want to buy these cool wheels? They’ll fit”. Showing ads based on a rough geo ip or the referrer is also fine. And that’s where it ends.