Postage Reply Mailed With Sierra Club Label

A couple of people at work look out for stamps on incoming mail for me. I got this one a couple of months ago and wondered about it.

I'm not 100% sure how this is supposed to work, but I'm pretty sure that a sierra club sticker isnt what they had in mind.

So...is it:

A: The sticker covers over the meter that charges the reply mail back to us?
B: The posties know that we are a not for profit and let us slide?
C: Chaos reigns at the PO?

It made me think back to stories I had heard about people gluing postage reply cards to bricks.

The area that the stamp covers has no mention of postal value or permit number. Therefore, the placement of the cinderella was a way to share the virtues of the Sierra Club in a legal though albeit fanciful manner.

Note that the permit number for business reply mail is not in the upper-left hand corner, but in a box above the address.

Aha!

I didn't see the permit number there. I assumed that the label covered the number.

I suspect this is the reason why it is where it is. :D