I would urge mozilla to remove all branding from the popup. It's gonna get really confusing when 3rd party popups get into the game (would they call it Google browserID or "google's version of persona"?). Second, since websites are not getting any private information from mozilla, mozilla is barely relevant. Third, while mozilla's work is commendable, users don't need a link to learn about the protocol and that it's benevolently "built by a nonprofit", instead they trust that the target website knows what it's doing by showing that popup.
I think the "built by a nonprofit" is a fantastic point that they should keep pushing, though.
"Sign in with your email address"
At Voost (https://www.voo.st/) we have been using BrowserID since launch earlier this year. We just use this simple phrase and users "get it" right away. There's no need for complicated branding.
1) Forced all users in your system, who already had email/password based accounts, to abandon their existing accounts and adopt Persona
2) Became fluent in quickly explaining to users how to reset their Persona password when they forget it
3) Don't mind losing all the users who say "I trust you, but not this company I haven't heard of before." Some users, especially jobseekers, won't let their circle of trust grow - and forcing adoption of a 3rd party causes abandonment. But so does a complicated sign-in process, so you just need to figure out if group A or group B is larger because you can't make everyone happy.
#2 has not been a problem, as far as we can tell. If users forget their passwords, the reset-password process on the Persona login dialog works great - better than almost every other password-based website I've used. In the long run, passwords are only maintained by primary IdPs like Gmail, so this is even less of an issue.
#3 is totally dependent upon your audience. We definitely get pushback on Facebook auth - you can't run a FB-only login system without alienating a significant chunk of most audiences. Initially we tried to encourage FB auth by making BrowserID less obvious, but that just produced a lot of angry emails from people who didn't realize they had an alternative. Now that Persona and FB auth are on equal footings, we have yet to have anyone complain about the signup process. YMMV.
Facebook blew it. They could have been identity for the internet, but with all the privacy and spam problems users HATE logging in with Facebook connect. We tried it for a website and it just failed. There's huge resistance.
What's your experience with that? Implementing OpenID tends to not be very fun (whether as a consumer or as a provider), is Persona better?
I love Persona. I want a Persona shirt and tattoo. OpenID was just a bit harder, but had nowhere near the payout that using Persona offers. The only burden of Persona is the auto-login/logout handling, which is a good thing in the long-run but in the short-run involves tracking down all your login/logout methods and making sure they all react properly.
*OAuth integration is a nasty mess of nastiness that I can't bring up w/o derailing this entire conversation. If you want to chat about that train-wreck, email me.
I'm curious how you deal with someone logging in with one system and then coming back and logging in with another. Do you have a way to merge accounts somehow?
Also, I clicked on yahoo and got this: http://www.evernote.com/shard/s178/sh/faba70e1-03e6-4448-81f...
Once a user's source authenticity is verified, we give the option to merge accounts once we detect overlaps. So if you login via Twitter, verify your Yahoo! email address through the profile, and then login through Yahoo!, you'll be in the same account as you were in the 1st login. We have ~20 scenarios that we maintain for logins, and have heard 0 complaints on the assumptions we have in practice.
Thanks for the screenshot - we'll get that fixed today. Would you like an email once it is resolved?
Teaches me to try and get Yahoo! to behave with https. If anyone wants a great example of why to use Persona, try using Yahoo's developer apps interface...
* Logo is ambiguous and looks like a generic button
* "Mozilla" in the name instantly steers away other browsers
We've implemented it on LinkUp (https://www.linkup.com/account/), love the technology, and REALLY hope the adoption of it takes off - but until I can explain it to a user in 2 sentences, it won't claim the throne.