Right, it's not the only identifier, but it's one of them, and you will "pollute" each other's targeted ads to an extent. I'm assuming some sort of adtech stuff

Right, it's not the only identifier, but it's one of them, and you will "pollute" each other's targeted ads to an extent. I'm assuming some sort of adtech stuff is happening at the carrier/provider level as well, independent of your browser or individual browsing device.