Sustainably? They don’t (mostly). Most are either pet projects, paid for out of pocket by the instance owner or run off donations. Neither are particularly sustainable long term, with rare exceptions like sdf.org.
The SDF runs just about every federated service you can think of, and has done so since the 1980s, run almost entirely off donations. Started as a dialup BBS (still active).
I donate to them because i believe in the cause. Its $1 per month, so not like its breaking the bank. But if every user donated the same, they would have more than enough to cover the bills
Or you could just to go the head admin's blog, where he does financial breakdowns of where the whole *.world thing is up to (they run multiple instances).
That’s awesome! Glad to see that my donations from canceling Reddit premium are making a difference. Hopefully the owners can eventually make an actual living off of this. Would be good for everyone involved
Make it $.01 and you might actually have a good idea on your hands. Big enough to matter given the thousands of users, small enough for the average user not to care.
The hard part is running a secure and private payment system on top of this.
Thanks for asking this. This is something I've been serious about for awhile. Turns out while it's expensive in the grand scheme of giant website it's not that expensive money wise. Though it is very time expensive.
IDK, I thought I saw they said it cost $300-400 a month to host, for a personal expense that's pretty significant for most folks (plus the time, though it seems to be a labor of love).
Oh that's for sure a big expense for most people myself included but if you go to the open collective link above the estimated budget for lemmy.world this year is only 16k ish. and thats to host one of if not the biggest instance right now. if every user donated a dollar the instance could run possibly for years.