[Thorrez]

You mean they redirect through various different domains not affiliated with Twitter before reaching the end? Who creates these links? Is it people creating short links before posting to twitter? What's the purpose? Just tracking?

[manmal]

Yes, my bet is on tracking.

[Thorrez]

Wait, my original question still is open. "Why not tweet https://twitter-unfurl-faker.herokuapp.com/"? If Twitter won't unfurl non-t.co URLs, then that "would break a lot of twitter‘s content."