[t4367]

Is it really that no one at all will pay or not enough people will pay to turn it into a billion dollar VC funded business? Could such a business perhaps be bootstrapped (while keeping a stable full-time job) and built with more modest goals in mind (say just support yourself and a small team)?

[sejje]

To be on the scale of social media, you'll need to be a profitable billion dollar business.

Nobody has supported billions of users with modest goals. It's nearly an oxymoron.