Usually "you are the product" is a snarky, low-effort comment, but this particular case seems like the rare situation where it actually is directly relevant. I

Usually "you are the product" is a snarky, low-effort comment, but this particular case seems like the rare situation where it actually is directly relevant. If you run a self-service advertising system, then don't advertisers count as users, and don't their ads count as third-party content that the system operator isn't liable for? They may not be your service's only users, and people may not like ads, and ads have a commercial purpose, and advertisers pay for them, but I don't think Section 230 cares about any of those things.