I tried the OpenPhoto example. One thing that introduces friction compared to username-password: The first time, I have to create a Persona account. Unfortunatelly, I'm not logged in afterwards.
Most sites nowadays log you in right after account creation and just wait for email-verification later. Is that even possible with Persona?
Yeah, that totally sucks, and we're working on it.
OpenPhoto is still using our old API, which can't handle post-verification redirects. Our new API does this automatically. Grab a mailinator account and try signing in to http://123done.org.
As for creating a Persona account, we're trying to fix that, too. Next month we'll be turning on a feature (codenamed "bigtent") that verifies Gmail, Hotmail, and Yahoo users by sending them through their respective provider's OpenID or Oauth endpoints. No more new account creation. No more email verification loop. Just three clicks and you're done.
The webpage should suggest a website other than OpenPhoto, then. First impressions count. (I say this as someone who's really excited by Persona and who wants it to spread as quickly as possible.)
Most sites nowadays log you in right after account creation and just wait for email-verification later. Is that even possible with Persona?