It's rarely a good thing to read about a company closing its doors, and I hope that you guys have more luck in your next venture, whatever it may be.
I suspect that you had a really, really tough time getting companies to pay you for placement (that is where you make your revenue, right? I don't see any other way). You've created some strange hybrid of, essentially, a gamified resume', and while the little graph is a neat trick, you probably figured out pretty quickly that companies with the money to throw at recruiting services simply do not care one whit about how many internet points a potential new hire has on some random site.
As a hiring manager, I can tell you what I'm interested in when seeing a potential new hire: a well-written, concise resume, links to code samples (whether on Github or elsewhere), and how well they're going to work with the rest of the team. Work for Pie appears to take the long route around coming up with an executive summary (of sorts) for just one of these three attributes. It seems highly impersonal and I'm surprised that you got any developers to sign up for it even with the promise of free internet points.
Also, I'm sure you found out the hard way about how intensely competitive the whole third-party-recruiting game is. It is not a market for the weak of stomach; I cannot tell you the number of phone calls I get as soon as I post an opening, and nearly all of these calls are extremely, extremely aggressive. Here's the average phone call: "Hi Mr. M242, I'm Recruiter from ColdCallCorp, and I saw you had an opening for a developer, I have a person coming out of JustShutteredStartup and she did X, Y, and Z, which I noticed on your listing, she has N years of experience and is extremely excited about coming to work for you, when can I tell her you're free to interview?" (This is without me saying any words past "Hello".)