Today we've enabled login by email address on Branchable, as an alternative to openid login.
So, all you need to make a site on Branchable now is an email address! Also, users can log into your sites on Branchable using their email.
We know that some Branchable users were relying on now defunct openid providers like Google and MyOpenid. We can switch your sites over to use an email address instead if you want; just get in touch.