Even amongst those who say they would pay $25/year for Twitter premium, we'd first have to account for stated vs. revealed preferences of how many would actuall

Even amongst those who say they would pay $25/year for Twitter premium, we'd first have to account for stated vs. revealed preferences of how many would actually pay. I can't speak about you as an individual, but study after study has shown that this can be a huge effect. And keep in mind, this is only among privacy minded tech people. The vast majority of social media users do not give a shit about this (and will explicitly say so). Also, I imagine the people who are willing to pay for Twitter premium are highly correlated with the people who constantly rail about social media and threaten to quit/actually do quit. For those people, switching to a paid model is just going to provide the impetus to go ahead and quit anyway. All of which serve to bring the per user expenses up, but then increasing the cost of online services usually prompts a huge hue and cry (see: every time Netflix ups their prices), so you can't keep up with inflation even. And so people start quitting, and then due to network effects everyone else also starts quitting and the service dies. This is not in Twitter/Facebook's best interest and rest assured, they will not ever do it.