And the customers who pay to see no ads are also exactly the people who would refuse to click on the ads anyway and likely also are running an ad blocker, so th

And the customers who pay to see no ads are also exactly the people who would refuse to click on the ads anyway and likely also are running an ad blocker, so the admen would have lost nothing (and possibly gained from not paying for wasted impressions). Having a no-ad tier means you can reasonably argue that those getting ads have opted into them, and thus are more valuable to the advertisers.