At least with Lemmy there's lots of different servers, each with their own running costs.

Each could try a different way of keeping the lights on. Some could run on donations only, some could use small unobtrusive ads on the side, some could do lots of ads. If any server does too little they'll go down due to lack of funding, if any server does too much the users will migrate elsewhere, as it's quite easy to make a new account on another instance and keep following the same communities.

Even if we end up with some large-scale instances with big servers, millions of users and serious money involved, they won't have a monopoly on all the content like with reddit, so the competition should keep them from doing anything stupid.

Well, we are on the ground floor here. Let's find something that keeps the lights on and gives everyone the incentives they need to make a great community!

Perhaps a good start would be a page that gives statistics about the time and money required to run an instance. I really appreciate those who have dedicated their time money and reputation to start things up. Lets find a way to build a better social media experience together.

I think many of us would be OK with a number of different models, donations, non-intrusive ads, reasonable subscription fees, etc. Perhaps there could even be incentives for people who put time into building communities by moderating or other tasks. The important thing in my opinion is that everyone feels they contributed to the structure in a way that they want to keep participating.

Edit: I found a budget page from the donation link on the side bar of the main page of lemmy.world.