You must then unsubscribe your library from every newspaper and popular magazine published. You must unplug all computers from the internet. You might as well poke out your eyes, plug your ears and live life through your nose. The two terms and the meaning of each are very different. You are right.
Advertising is in the magazines and popular press things.
Advertising is everywhere and you can't and should not bat another eye at its presence. I'm a publisher. I've been miffed by various librarians and even bookstore managers who have rejected some of these titles out of hand because of their back-cover advertisings. Case in point. We published a 400 page trade paperback with 300 illustrations by 4-time Olympic water polo coach.