Considering what they get in return for hosting all those free OSS projects, I'd say they're more than breaking even, so let's not pretend like they're doing anyone a favor here. Github would simply not be nearly as big if it wasn't the de facto storage option for most OSS projects. All these OSS projects are their marketing. My point is that they're not hosting OSS projects out of the goodness of their heart or out of service to some community. That's the core of their business. Their greediness is, of course, debatable.