Exactly, some implementations can even lock it to a single "message" (what you see on the credit card statement) so that it can't be used for a different purcha

Exactly, some implementations can even lock it to a single "message" (what you see on the credit card statement) so that it can't be used for a different purchase. Needs cooperation from the merchant not to put the subscription date in the message but otherwise, it's not exactly rocket science.