Long long term is anyone's guess, but I think if the team stays mission driven and doesn't get distracted they won't have any problems with money. The company is still owned by employees, and the entire team is just 20 people. They don't seem to have a bloated stack or unnecessary features. They got a sizable initial war chest of $14 million from Twitter. When that runs out I bet adding just a "donate" button somewhere on the site will be enough to cover expenses.
14 million pays for a couple salaries and a few server bills. That burns away fast when users get higher and higher into the tens of millions.
Being mission driven and not getting distracted is nice, but that doesn't put money in their pockets. Firefox and other products that are/were beloved by similar crowd have been asking for donations for years and it hasn't worked out. Wikipedia seems like the rare exception that pulls it off, and that's because they're aggressive with their campaigning for cash and they're basically an indispensable public service at this point.
Already raised another 15 million from Blockchain Capital. Not a donation, but a Series A. They could have walked the nonprofit donation route like Signal but they dance with VCs instead.
https://www.blockchaincapital.com/blog/bluesky-13m-users-and...