If only 2% of New York Times online visitors trigger the 20 per month article threshold, their former mass advertising audience turns into a niche of self-selecting paid customers.
There has never been a mass market for good journalism in this country. What there used to be was a mass market for print ads, coupled with a mass market for a physical bundle of entertainment, opinion, and information; these were tied to an institutional agreement to subsidize a modicum of real journalism. In that mass market, the opinions of the politically engaged readers didn’t matter much, outnumbered as they were by people checking their horoscopes. This suited advertisers fine; they have always preferred a centrist and distanced political outlook, the better not to alienate potential customers. When the politically engaged readers are also the only paying readers, however, their opinion will come matter more, and in ways that will sometimes contradict the advertisers’ desires for anodyne coverage.
See also: The Times’ Paywall and Newsletter Economics, from a year ago