tl;dr: My understanding is that an advertiser can use ads on the NYT to profile its audience, then use that profile to target the same audience on cheaper sites.

I can't find the link now, but I've read that this practice is killing the economics that drive the production of quality content. Quality content is expensive but it attracts a higher-value audience, and sites make it with the expectation they can pay for it by charging more for ads shown to that audience. However, that audience also consumes low-quality content, and smart advertisers realized they can get more bang for their buck by running "research ads" to profile the high-quality site's audience, but then target that same audience on low-quality sites.

So ad targeting discourages the production of quality content, and encourages clickbait and memes in its place.