Quote:
Terminology: You have a meter stamp with an accompanying pictorial/slogan advertisement - applied privately by the mailer and a nice collectible piece of postal history.
It is not a postmark, nor a cancellation, which would be applied during postal processing and generally not applied to metered mail.
I disagree,
I'd suggest the centennial slogan is part and parcel of the Borough's Pitney Bowes meter machine.
Applied both at the same time.
Slogans as part of company's meter machines are quite common.
(Free advertising)