This site is currently struggling to handle the amount of new users. I have already upgraded the server, but it will go down regardless if half of Reddit tries to join.
However Lemmy is federated software, meaning you can interact seamlessly with communities on other instances like beehaw.org or lemmy.one. The documentation explains in more detail how this works. Use the instance list to find one where you can register. Then use the Community Browser to find interesting communities. Paste the community url into the search field to follow it.
You can help other Reddit refugees by inviting them to the same Lemmy instance where you joined. This way we can spread the load across many different servers. And users with similar interests will end up together on the same instances. Others on the same instance can also automatically see posts from all the communities that you follow.
Edit: If you moderate a large subreddit, do not link your users directly to lemmy.ml in your announcements. That way the server will only go down sooner.
Is there a tipping point where it's a net loss? If I understand the protocols correctly, the whole back end federation part of the equation is push based, so if everyone was running their own instance, lemmy.ml would have to push every post to every individual instance in the network. At some point isn't it more efficient to only have to serve posts when people come here to look at them?
Network pushes like that aren't resource intensive at all.
The only negative IMO, is community discovery. Which tools can always come out in the future that help with this. We could even embed these into lemmy-ui in some way.
example: https://browse.feddit.de
Oh another one: redundant hard drive space.