It's not really an advertisement to Apple.
It just shows your customers that they have multiple options when it comes to paying at your business.
Same way you see Mastercard/visa/discover/american express stickers on the door when you walk into a place or near the credit card terminal.
Many people including myself like to use Apple pay not only because it's easy, simple and fast but for the added layer of security where the merchant does not have access to our real credit card number.
I like it OP.