Why would you subscribe to something you can have for free? For instance, practically every mobile game is free--either literally free and supported entirely by ads, or freemium, where it's literally free but you can pay to get various perks. The idea that someone will subscribe to an existing service which already isn't considered to be super-high-value seems naive.

Also, how do you "build algorithms that promote good ideas" without regulating the content of the idea? This is beyond the capability of most people to figure out, and machine learning capabilities generally are a fair bit short of what people can do. So how do we know this isn't akin to saying, "Make gold out of lead"?

If it can be done, yes, it sounds great. But can it? And can it be done without the algorithm just squashing free speech by functioning as a conventional-wisdom-detector only?