>> On the other hand that's not enough for a business

It could be. Once Facebook had everyone on board they could have pivoted to a model where people pay directly. It's easy to forget how incredibly useful it was in the early years. It's not enough for a business that needs to endlessly grow but businesses don't NEED to do that - especially tech companies where costs can be incredibly low once the initial website is built.

20 years ago I'd say that "free-to-play" would have been necessary because of the N² value that social sites create, just getting the idea mainstream was difficult enough and you can very much see the phases we went through, how Facebook inspired Twitter and back, etc. Like, of my family and friends who are on Facebook I think very few of them would become subscribers.

Today people believe in the value of social media and selling a subscription would be easier but the barriers I see are

- from the viewpoint of incumbents, the people who would pay to have an ad-free experience are the people you most want to show ads to! Or to the converse, the person who won't spend $10 to block ads is cheap and won't spend money on anything else

- incumbents will get in the way of any kind of "aggregator" service which adds value

In a Fediversal system there would be a possible markets for a product that helps a consumer have a better consuming experience or a publisher have a better publishing experience (e.g. I post links and photos to 9 services) and would some pay, yes. But incumbents are threatened by openness and price API access at punitive, not profit-maximizing levels. Even in a more open world I'd have a lot of fear that the revenue and the costs won't line up and the profits in some part of the systems will be at the expense of unsustainable losses elsewhere and the mechanism design to make that work is tough.

(e.g. I did some biz dev with a guy who had a track record in influencing freakin' telecoms to do better with mechanism design who thought "freedom isn't free" is the problem with the internet who struggled to get calls with anyone)