which do y'all say? And if you say "q-pon" - well, why? since when is "cou" ever pronounced "q"?

just curious! all this talk of envelope ahnvelope reminded me - there used to be a clever radio commercial in which there were two voices, and one said "envelope" and "coupon" and the other said "ahnvelope" and "q-pon" - the two were always correcting each other. I think there was at least one more word in there with two accepted pronunciations they corrected each other on....

but WHY Q-PON?! I don't understand....