https://www.cnet.com/news/mark-zuckerberg-defends-facebook-advertising-model-we-dont-sell-peoples-data/

In what has now become a familiar tone from the CEO, Zuckerberg tells us the common questions and concerns he gets from users about Facebook's model, in his words, and the answers he has to offer, all in a bid to "explain the principles of how we operate."

The first fact on offer? Ads keep Facebook free.