As for the answer to the implicit question...the best people are passed by reference when they're already recognized. We're aiming to help people show that their skills have value when they don't have a reference.
The number is just, well, a pointer to a broader portfolio - and we'll only be making that portfolio more expressive over time.
There are also plenty of ways of circumventing this. Since a test taker is evaluated not just by his answers, but also by the process of inputting his answers, that itself could also be faked away.
While I don't think the point of this idea is to evaluate the candidate's personality, I'm wondering if the founders thought about this. Is this going to be left to the companies to figure out on their own, or are the founders going to assist in this? What I don't like is the idea of encouraging employers to filter candidates by coding skills first, then personality. As a project manager, I've dealt with my fair share of really intelligent but lazy, egotistical engineers and thinking back I wouldn't really hire them had I known about their personalities earlier. I would rather hire engineers with B+ coding skills and A+ personalities, than engineers with A+ coding skills by B+ personalities.
You're the hiring manager. I'm a professional programmer who works with you. Let's say I personally know and can vouch for the ability of 100 programmers. There are 7 billion people on the planet. What's more likely? That your best candidate will come from my 100-person address book, or that it will be one of the other 6,999,999,900 people in the world you're not looking at?
Now it is likely that someone from my address book will be, on average, a better candidate than a random selection from the rest of the world, but all that shows is that professional references will produce "above average" candidates.
EDIT: I suppose the difference is whether you want the "best way to find good people," what the parent said, or a "good way to find the best people" which I argue referrals might not be.