Recently I've started running my own lemmy instance, as part of my decoupling from Reddit, due to them speed-running enshittification. The instance has been growing nicely and holding up very well indeed. but there's dark clouds forming on the horizon, as more of more of the early adopters and peopl...
It's useful data. You can see which domains have been checked by others as not-spam and which have been endorsed by other instances. How you use this data is up to each instance, but once it grows large enough it could be used for spam detection, or for whitelisting.