Bound Printed Matter

So the post office guy told me I couldn't send magazines media mail, like I have been sending them, with no complaint from the post office, for simply ages. Having read about this controversy from other zinesters, I explained that they were periodicals and that their advertising content was way, way under the threshold percentage (sigh). He said they couldn't have any advertising. I went online and did some research and...he is right. If they have any advertising at all, they have to go as "bound printed matter", not "media mail". Bound printed matter is cheaper than parcel post. For this mailing (not necessarily all mailings, though, because the weight system that determines what is cheapest is mysterious and complicated), however, first class is cheapest. Yay, newsprint.