An administrative announcement.
Motherfuckers.
https://mastodon.cloud/media/oxNPAqhKHeUAAvMv1X8

Q: What's this "Federation thing?"

A: A bunch of communities, on different servers, sharing /some/ but not necessarily /all/ of their traffic. Or, in some cases, none. It depends.

The User Guide has a good section:
https://github.com/tootsuite/mastodon/blob/master/docs/Using-Mastodon/User-guide.md#decentralization-and-federation

Q: It sounds as if that's complicated. Do you have a picture you can share?

A: @vhf made one: https://techn.ical.ist/users/vhf/updates/102

It misses a few edge cases, but mostly, that's how the spice flows. Er, toots.

@dredmorbius @vhf Interesting. I did not understand that if someone is not followed by *anyone* on an instance, then *none* of their tweets appear in the federated timeline. So the "federated timeline" is only those users who have some connection to your instance. This means that the larger instances (ex. mastodon.social, mastodon.cloud) will have a bigger and richer federated timeline by virtue of having more people who will follow others on other instances.
@danyork @dredmorbius @vhf This is an important restriction that allows for "Live and let live" aspect of federation. Total "open" federation will be polluting; strict "following" federation will restrict organic growth. This is a happy medium while maintaining a happy medium. I think we shouldn't focus on "larger" instances; instead instances that have a well defined "tribal" attribute.
@Aswath @dredmorbius @vhf Good point about finding a happy medium. My point was really that the "experience" of "federated Mastodon" will vary based on the size of your instance. On a large instance, the "federated timeline" might have many entries and give you a view of a "firehose". On a very small instance, it may seem like few people are in the federated timeline. It might make people there wonder what all the buzz is about.