I used it for my company at the time as part of a dual-auth system (Facebook / Persona). We were even featured as an example on the Persona dev website. The ser

I used it for my company at the time as part of a dual-auth system (Facebook / Persona). We were even featured as an example on the Persona dev website. The service worked great, even for my technically-not-literate audience. And it was reliable (we sold event tickets).