I don't understand.
They use single text box of OpenID login.
They have it separated from login page in another page.
How do they want it to be successful and where is their ultimate usability mastery?
There is no way OpenID can be improved when there is no interest in solving global internet issues. Neither Facebook for implementing the own mechanism nor 37signals would get medal of honor for uniting the internet.
The key problem didn't come from people NOT using OpenID, but from the people who did. Supporting OpenID is a nightmare. You have different relaying services that go up and down (OpenID's answer is: "use more than one" - ha!), various levels of incompatibility, and a generally user hostile experience.
If OpenID usage had been in any serious numbers, our support department would have revolted.
If you're trying to build a profitable online business, cutting your support costs is key. And the easiest way to cut your support costs is to dump confusing features or technologies that people constantly write in about.
Same reason we originally dumped FTP in favor of hosting files ourselves. The support costs were way too high.
The worst part the description of what OpenID is design for is too much promising. Those who retire OpenID never going to give another chance. Everybody will be waiting for new alternative but that's kind of everything from the beginning.
The story of OpenID (not)success sounds like the html compatibility issue. Overall, time pass by and it starts shaping up. But probably no lessons learned from it (yet).
And when the big players are giving up on it no way small startups will be able to maintain, improve and support OpenID features.
There is no way OpenID can be improved when there is no interest in solving global internet issues. Neither Facebook for implementing the own mechanism nor 37signals would get medal of honor for uniting the internet.