As of today, Firefox Affiliates has switched to BrowserID for users on the EN-US locale. If you previously had an Affiliates account, you can sign up for BrowserID with the same email address you used for signing up with Firefox Affiliates. If you’re not a Firefox Affiliate (shame on you!) just sign up using BrowserID and you can host Firefox buttons of all kinds on your website or blog.
We’ll be adding BrowserID in our other affiliate locales in 2012. If you’d like to learn more about BrowserID and how it works, this post on the Hacks Blog is a good primer.
Kudos and thanks to the Affiliates and BrowserID teams for getting this live. We’re pretty excited to have this up and running only a few months after launching the new Affiliates program.

“If you’re not a Firefox Affiliate (shame on you!) ”
LOL
This is great. I’m anxious to see all Mozilla sites and services (and hopefully others around the Internet) implement it.