Sure thing Facebook has nice servers architecture and most brilliant engineers, but does FB creates any content? That's just a website, an empty shell where people upload content. And FB gets 100% of ads revenue, generated by others' content. Look at content creators like The New York Times's website, they get money through ads by attracting people thanks to their article. Plus you give up all of your rights and privacy, in exchange of a free service. I think the idea is not to "start paying users", but creating a fair platform.