There's a section titled "Streaming and Hosting Affiliation" in the article that answers that. Fly-by-night file hosts that pay for hits and serve a billion malware popups to visitors.
Usually I go to the network tab and pull a direct stream to the file hosted, but some even go as far as streaming using specialized clients that chop up the video and apply encryption (which I assume is easy to defeat but not worth the hassle when the whole point is to avoid the hassle of ads)