One other thing people may not realize. If you use your credit card at a merchant online or in person and you associate any information such as a telephone number or email with that card. Any time you use that card, online or off, to make a purchase with that merchant those transactions can be tied together regardless of whether you provide your email/phone on future transactions. Large vendors such as walmart etc no…
okay... i'll bite: how does one use a card online without providing phone or email?
You don't always have to provide a phone number, either. Most of the time yes, but I don't think the phone number is actually required to complete a credit card transaction.
There also used to be credit providers - maybe there still are? - that would let you generate a new card number for each purchase. That too may accomplish nothing from a tracking perspective, since the credit provider would be able to match up all the numbers. But, if I had that capability, I would use it.