I think that if you look at elance/odesk/upwork, you can actually rule out all of those developers because they get paid through the upwork platform - they woul

I think that if you look at elance/odesk/upwork, you can actually rule out all of those developers because they get paid through the upwork platform - they wouldn't be sending invoices based on their git history. They might have other clients that they invoice directly, but I wouldn't count on it.