Why is my userid in links I copy? [duplicate]

Question

If you right click/copy "link", your user id is appended at the end of every link you create.

e.g. https://stackoverflow.com/a/271517/111307

I am 111307, and I have nothing to do with the question linked here or its answer, of course.

I am not hyper concerned about privacy, but why? What's the point of this?

I'm assuming this is some kind of way to figure out which users are bringing traffic. Are we going to get rep for this or something?

Answer 1

This is indeed for tracking purposes.

You don't get rep for it, but three publicity badges: Announcer, Booster, and Publicist for linking 25, 300, and 1000 people to a question.

Answer 2

Yep, you guessed it. It's for determining who gets badges like these:

(I think that's the only use)

You can remove the userid, though, and it'll work fine.