VizillaKarma

And while you're looking at email addresses, I suggest another item to look at: email names matching users' actual legal names. For example, does a match (i.e. John Smith with an email address johnsmith@gmail.com) do better than a non-match (i.e. Sally Jones with email address of prettypinkprincess924@yahoo.com)? I'm guessing that you'll find people with what I'd call grown-up email addresses (matches) have higher credit scores than those who don't.

Funny, I found something similar in my line of work (lead generation), where leads with broadband ISP email addresses outperformed Gmail, Gmail outperformed Hotmail/MSN, and Hotmail/MSN outperformed Yahoo.

Someone who has a broadband ISP provider email address like Comcast has money to afford the service in the first place. It would be interesting to see how much or how little the variations vanish between email domains if you could just look at the users' connection speeds when checking in from non-work IP addresses.