Why you should have a public location for your branch

I asked this self-same question on the Bazaar mailing list the other day. Here's the answer:

• Given that the place you push the branch to (its "push location") might be different from the place that others get the branch from, branch's have public locations.
• Any tool that shares your branch with others (e.g. bzr send, a commit notifier or even lp-open) needs to have a public location to share with the world.