You implement OAuth 2 on your side, so you're not tied to a proprietary API forever. (You can think of it as an OAuth proxy.) If you already have implemented Facebook OAuth, you can plug us in and add Email, Twitter, etc., with almost no additional work.
Our Username / Email / Password flow (and APIs) are more dev and user friendly than Janrain's -- which has been more focused on social.
If you use Ruby, you can use our Gems to get set up very quickly.
We're also cheaper since our feature set is closer to Janrain's Enterprise; you can get started today without talking to a sales guy.
Our homepage also has 100% less lightning animations. ;)
Happy to answer more questions here or via email: juliuss@dailycred.com
You will have to store your user info yourself, but it does take care of oAuth for you. Full disclosure: I work for AddThis and worked on this feature.
