It is led by managing director Gabe Newell (who only exercised his veto a few times). It's amazing they're able to pull this off, creating a gaming platform of 40 million active players. Would it have been the same with traditional hierarchical structures?
Maybe not. Both Steam (gaming platform) and Steemit are not final products. They should be expected to evolve over time, building on the wisdom and experience of both users and creators. Having a digital platform helps with rapid prototyping and constant iterations. And in Valve's case, teams are usually formed organically as people gravitate towards the activities that best suit their individual motivations.
Clearly I've yet to see another arrangement that inspires me. So it's something that I want to keep sharing here. The video below is quite a good primer on Valve's policies.
Check out their handbook too: http://www.valvesoftware.com/company/Valve_Handbook_LowRes.pdf
@kevinwong