Er, no. Facebook is monetizing user-contributed content by slapping their own advertising across it with no kickbacks to the contributors. There is an asymmetry

Er, no. Facebook is monetizing user-contributed content by slapping their own advertising across it with no kickbacks to the contributors. There is an asymmetry here; FB are creaming a profit off this material, in addition to covering their running costs. FB also has the 500lb gorilla of network externalities on its side. For example, I dislike FB but I can't afford not to have an FB account: because 500 million other folks are on FB, there's an internal email system that doesn't interoperate with other networks, and some of those folks are (a) clueless enough not to have a non-FB email account and (b) important enough to my personal or business life that I need to communicate with them. So perforce I must use Facebook. The high-value content-contributing users were a critical part of FB's growth dynamic insofar as they attracted other users (whether that's so now is another matter). But they get no monetary or in-kind reward for their activity. I will concede that the term "cognitive slavery" is a bit over the top, but platforms like FB are very carefully designed to hit our reward feedback loops and make us feel good for coming back and feeding stuff to them, to the point of fostering addiction-like compulsive behaviour. This is, at best, unethical and at worst exploitative. And that's what's in play here -- FB make no pretense at doing this for anyone's benefit but their own.