It may be viable to run a small/medium website on ad revenue, because a small/medium website doesn't cost much at all. Hacker News is famously run on 2 boxes.

It may be viable to run a small/medium website on ad revenue, because a small/medium website doesn't cost much at all. Hacker News is famously run on 2 boxes. And that is without Cloudflare + CDNs to cache static requests: static websites are practically free. Domains are cheap as well, even a .com domain costs $20/yr and domains like .xyz cost <$5/yr. The cheapest linode cloud server costs $5/month. Idk how much ad revenue pays out but I imagine it can recover those costs. However, you probably won't profit from ad revenue, and it definitely won't sustain a full income.