The more you pay for a subscription, the more valuable it is to advertise to you -- maybe the classic example is The New York Times which has highly annoying advertising if you're a subscriber because you've qualified yourself.
Or rather, if you believe you are too poor to afford a $10 a month subscription you probably believe you're too poor to afford anything that is advertised. The model of "premium subscription with no ads" flies in the face of reality.
I would be willing to consider paying for vetted ads - in other words, you pay for the NYT and you get a guarantee that you're only seeing ads that have been personally vetted by the NYT for correctness, appropriateness, etc.
Advertising is speech and it used to be that if a magazine/newspaper printed a scam ad, it was horribly damaging to their business, both legally and morally.