Apart from Spam, phone number is also one of the few unique identifiers, which is valuable to, among other things, to ID you cross-channel and show you ads. It

Apart from Spam, phone number is also one of the few unique identifiers, which is valuable to, among other things, to ID you cross-channel and show you ads. It is easy to create a new email, but not so easy to create and keep a new phone-number.